Sebastian Vettel clinched his fourth Formula 1 world title with victory at the Indian Grand Prix this morning.
The German lost the lead twice to Red Bull teammate Mark Webber, but the Australian retired from second place late on with an alternator failure.
Mercedes' Nico Rosberg finished second, while Romain Grosjean of Lotus came from 17th to secure the final place on the podium.
Red Bull also secured the constructors' title.
Read how all the action unfolded below:
Good morning! It's around half an hour until the drivers will leave the grid for the start of the Indian Grand Prix in New Delhi. Both the drivers world championship and the constructors title can be won today.
Sebastian Vettel will win the drivers' title for a fourth year in a row if he finished in the top five today. Should he fail to do so, Ferrari's Fernando Alonso, who is the only driver still able to pass Vettel in the standings, would have to finish in the points to keep the title race open.
Despite starting from pole position, the German can expect a battle for the race win this afternoon. Vettel will start the race on the soft tyres, which are expected to last for a maximum of 10 laps, while teammate Mark Webber, who starts fourth, and Alonso, who qualified in eighth, will both be on the more durable medium tyre for their opening stint of the race.
Further down the field, Force India's Paul di Resta is expected to be pushing for a place in the points this afternoon. The Scot, who will start from 12th, has been hampered by a case of Delhi Belly so far this weekend, but has confirmed that he is feeling better today. Meanwhile, Romain Grosjean's engineers got their strategy wrong in qualifying them yesterday, leaving the Frenchman down in 17th. As his teammate starts from sixth, Grosjean should have much more pace than those around him, and could move through the field quite quickly in the early laps.
The majority of the cars are now on the grid with around 15 minutes until they set off on the formation lap. This is just the third year that the race has taken place in India, with Vettel winning of both previous occasions. However, India is not on next year's race calendar, but it is hoped that it will make a return in 2015.
McLaren could be a surprise package today. Both cars made it into Q3 today, and will start ninth and tenth on medium tyres, having shown strong pace earlier in the weekend. The Woking-based side are still looking for their first podium of the season, and this could be their best chance for a top three finish.
The mechanics are just a few minutes away from leaving the grid and heading back to their garages ahead of the race. McLaren have just shared this pic of Jenson Button's team finishing their preparations.
PREDICTION! With the start of the race almost here, let's make a quick prediction. Vettel has been in a league of his own so far this weekend, but Webber's tyre strategy should give the Australian the upper hand. I wouldn't be surprised to see Webber get his first win of the season today, but barring a mechanical problem, the top five finish that Vettel needs to be world champion again shouldn't be a problem.
Today's race will be 60 laps of the 3.191 mile circuit. There are also two DRS sections, giving the drivers plenty of opportunities to overtake.
FORMATION LAP! Sebastian Vettel leads the drivers away from the grid.
The cars come back around onto the home straight ready for the start of today's Grand Prix.
LIGHTS OUT! Lewis Hamilton makes a good start but can't get ahead of Vettel. Alonso also makes a strong move, immediately pulling up behind Webber, but he makes contact with the Red Bull.
Raikkonen is on his radio to say that he has also had contact with Webber, who has dropped down to seventh. Massa has been the big winner so far, he managed to keep out of trouble and sneak into second. Vettel leads by 2.4 seconds at the end of the first lap.
Di Resta and Vergne have already come in for fresh tyres, while Vettel is also going to be coming in at the end of this lap. The soft tyres really don't seem to have any durability.
Alonso has also pitted, and he gets a new front wing following his collision with Webber. Vettel's stop means that Felipe Massa now leads the race. Daniel Ricciardo has made good progress so far, he's up to eighth in the Toro Rosso. Caterham's Geido van der Garde has been complaining of damage following contact with Max Chilton.
It looks like Alonso also clipped Button on the opening lap. While his front wing has been changed, he's now complaining that his steering feels heavy, so it could be a bigger problem for the Spaniard, who is currently running in 20th. Meanwhile Webber has moved back up to fourth as he slips past Raikkonen, and Grosjean is up from 17th to 10th.
Button appears to be changing his race strategy as he comes in to swap his medium tyres for softs. It may be that he sustained damage during his contact with Alonso earlier. Rosberg is also coming in for new tyres from second. He's done well to get almost eight laps out of the soft compound.
Raikkonen and Button are wheel to wheel as they battle for sixth place. Massa pits from the lead, promoting Webber to first place, with Perez second and Ricciardo third.
OUT! Van der Garde has been brought into the Caterham garage, ending his race. The team says that his first lap contact with Chilton broke the front wing and caused damage elsewhere on the car.
TOP 10! 1. Webber, 2. Perez, 3. Ricciardo, 4 Grosjean, 5. Vettel, 6. Sutil, 7. Gutierrez, 8. Massa, 9. Rosberg, 10. Bottas
Vettel manage to slip stream past Grosjean to move up to fourth. The Lotus driver is still on his first set of soft tyres, and it looks like it's hurting his pace.
The stewards have confirmed that they are investigating Sauber's Esteban Gutierrez for a jump start. If the Mexican is found to have left his grid box early, it's likely he'll be handed a drive-through penalty.
Vettel manages to find his way past Ricciardo, who will be his teammate at Red Bull next season. Meanwhile, Button is in for his second pit stop of the race.
After 14 laps on the soft tyre, Grosjean finally comes in to the pits, rejoining the race in 15th place.
Webber's lead is up to 7.3 seconds while Perez continues to keep Vettel in third. It has been confirmed that Gutierrez will have to complete a drive-through penalty for his jump start.
Perez asks his race engineer whether he is still on "Plan A", and it's confirmed that he is. At the moment, Vettel is the only driver running in the top five to have made a pit stop.
As Vettel gets closer to the rear wing of Perez, the McLaren driver is told that he is not racing the German, so not to waste his tyres battling with the Red Bull. If Webber were to pit from the lead not, he would drop down to fourth or fifth, so it looks like starting on the soft tyres has worked out well for Vettel.
Alonso is still trying to work his way back through the field following his lengthy pit stop for a new front wing earlier in the race. He patiently works an overtake to get past Gutierrez for 12th, but the Mexican quickly wins the place back with DRS.
TOP 10! 1. Webber, 2. Perez, 3. Vettel, 4. Ricciardo, 5. Sutil, 6. Massa, 7. Rosberg, 8. Hamilton, 9. Bottas, 10. Hulkenberg
Vettel moves up to second, outbraking Perez headind into turn one. Back in the battle for 13th, Alonso finally manages to make a move on Gutierrez stick.
Despite dropping down to third, Perez's engineer says that he is doing a good job of saving his tyres. It looks like the Mexican could be on for a good finish for McLaren. Perez's best finish of the season so far is sixth.
It sounds like Kimi Raikkonen has a problem with his car overheating, as his engineer has asked him to try and cool the engine on the straights. Meanwhile Rosberg manages to overtake Massa, but runs wide turning into turn 15, allowing Massa to move back in front.
Hulkenberg powers past Maldonado, but it sounds like he's been asked to give the place back for running off the track, as he's arguing over his radio that he did not gain an advantage by running wide.
Nico Rosberg is in for his second pit stop of the race. He managed a longer than expected stint on the softs, but is one of the first of the front runners to shed the mediums, so he could be struggling for grip late on.
Mark Webber also comes into the pits, and switches to the soft tyres, so this should be a fairly short stint for the Australian. Vettel now leads.
The stewards are being put to work again, after Grosjean complains that he was unfairly blocked by Gutierrez while trying to overtaken the Mexican on the pit straight. The Sauber driver has already had one penalty this afternoon.
TOP 10! 1. Vettel, 2. Webber, 3. Ricciardo, 4. Sutil, 5. Massa, 6. Perez, 7. Hamilton, 8. Hulkenberg, 9. Raikkonen, 10. Bottas
Hamilton has now dropped down to 12th after making a pit stop, while Vettel is also on his way into the pits, promoting Webber back into the lead. However, he should be coming in again soon to get rid of the soft tyres.
Webber has come back into the pits and is back on the medium tyres, allowing Vettel to take the lead again. The Australian comes out behind Ricciardo, but the Toro Rosso driver will need to stop again soon.
Hulkenberg's earlier overtake on Bottas is also being looked at the by stewards. The Sauber driver gained a place by leaving the track, but claimed the Finn forced him wide. After setting a new fastest lap of the race, Vettel is warned that he needs his tyres to last until the end of the race.
Webber is also being told to make sure his tyres make it to the end of the race. He's managed to find his way past Ricciardo to move up to second, but is 13 seconds adrift of Vettel.
Raikkonen moves up to third, using the slip stream of Adrian Sutil to move past the Force India, which is on old tyres. Meanwhile Alonso comes into the pits and re-enters the race in 16th. If the race were to finish now, the drivers and constructors titles would both be heading to Red Bull.
OUT! It's all over for Caterham today, as Charles Pic is forced to retire with a KERS problem. That's both cars out of the race now for the Oxfordshire outfit.
Having lost five places while on well-worn tyres, Ricciardo comes in for new tyres, dropping him down to 14th. There could be a problem for Webber, as he's told he has a gearbox sync issue.
OUT! Webber has to pull off the track. It's believed that the problem was caused by an alternator failure. It's disappointing for the Australian, who was many people's pick to win this race today.
TOP 10! 1. Vettel, 2. Raikkonen, 3. Sutil, 4. Rosberg, 5. Grosjean, 6. Massa, 7. Hamilton, 8. Perez, 9. Hulkenberg, 10. Di Resta
If my maths are correct, Vettel's increasingly likely race win would still be enough for Red Bull to win both titles today, while Mercedes would move up to second in the constructors' standings.
The stewards have said that there will be no penalty for Gutierrez for blocking Grosjean earlier. The Sauber driver is currently running in 11th.
Sutil, Gutierrez, Bottas, Ricciardo and Alonso are all within 0.7 seconds on the track in the battle for the final points place. Back up front, Raikkonen has been told to try to save fuel without losing too much pace. The Finn is still likely to need a pit stop, having stopped just once this morning.
Rosberg is told that his tyres are lasting well. The Mercedes driver looks good for a second place finish once Raikkonen pits, but he's over 30 seconds behind Vettel.
Grosjean appears to be managing his tyres well. The Frenchman has been on his current set for over 30 laps, but has just set his fastest lap time of the race.
TOP 10! 1. Vettel, 2. Raikkonen, 3. Rosberg, 4. Grosjean, 5. Massa, 6. Hamilton, 7. Perez, 8. Hulkenberg, 9 Di Resta, 10. Sutil
Rather unusually, Vettel has been told to stop using his drinks bottle. The device is linked to the car's battery, so they could be concerned about his alternator, having seen the part fail on the Webber's Red Bull earlier. Meanwhile, it's looking increasingly likely that Raikkonen will be going to the end of the race on this set of tyres, but the well-worn rubber allows Rosberg to cruise past the Finn to clinch second. Grosjean could also catch his teammate before the end of the race.
Hulkenberg drops out of the top 10 with a slow pit stop. Vettel sets a new fastest lap of the race, but is told not to push, with his engineer claiming that they have enough problems already. Could there be a second retirement on the cards for Red Bull this morning?
OUT! Hulkenberg is back in the pits with what appears to be a problem with the floor of his car, prematurely ending his race.
Grosjean is wheel to wheel with Raikkonen, and manages to slide past his teammate but runs wide, so he has to give the place back to the Finn. However, with Massa closing in on both of them, Lotus tell Raikkonen to let the faster Lotus past.
Massa also manages to sweep past Raikkonen, but Grosjean should have enough pace to keep hold of the final podium spot for Lotus. Hamilton and Perez are already closing in on the 2007 world champion, who is crawling around the track. His tyres have completely given up.
Raikkonen, Hamilton and Perez are three-a-breast down the straight, and Perez manages to come out on top, moving up to fifth. If he can keep Hamilton behind, it will be his best finish of the year.
Raikkonen has come in for a late pit stop, and he manages to get out in front of Di Resta. There are more problems for Lotus though as Grosjean is having to short shift.
Vettel is on his final lap, with a 27 second advantage.
SEBASTIAN VETTEL WINS THE INDIAN GRAND PRIX!
It's a race win and a 2013 drivers' title win for the German, who is followed home by Nico Rosberg, while Romain Grosjean completes the podium.
The win is also enough to secure the constructors' title for Red Bull for the fourth year in a row. Team principal Christian Horner admits that they were worried about the reliability of Vettel's car, but the German rarely looked troubled this afternoon, and he pulls onto the home straight to do some doughnuts to celebrate his title win.
TOP 10 & POINTS! 1. Vettel (25pts), 2. Rosberg (18pts), 3. Grosjean (15pts), 4. Massa (12pts), 5. Perez (10pts), 6. Hamilton (8pts), 7. Raikkonen 6pts), 8. Di Resta (4pts), 9. Sutil (2pts), 10. Ricciardo (1pt)
While all the headlines will go the Vettel, Grosjean's performance was also impressive this morning, coming through the pack from 17th to finish on the podium. Meanwhile, Force India will be pleased to have both of their cars in the points at their home race.
That's all from the Buddh International Circuit this morning, but stick around for reaction to today's race, and join us again next weekend for the Abu Dhabi Grand Prix. Until then, thanks for joining me this morning, goodbye.
