Arsenal travelled to Bradford City, a club 65 places below them in the Football League, for a Capital One Cup quarter-final this evening.
Arsene Wenger named almost his strongest XI but the Gunners were downed on penalties after a rousing 120 minutes from the home side.
The hosts had taken the lead through Garry Thompson but were denied a famous win in 90 minutes when Thomas Vermaelen headed an equaliser late on.
Read how the drama unfolded in our minute-by-minute updates below.
Evening all, should be a real cracker of a cup tie to warm us all up a bit!
With just under an hour until kickoff (7.45pm) we're still waiting on team news from Yorkshire.
Just as I say that, the Arsenal XI comes in!
Szczesny; Sagna, Vermaelen, Mertesacker, Gibbs; Wilshere, Coquelin; Ramsey, Cazorla, Podolski; Gervinho
That is a really strong starting lineup! Arsene Wenger is clearly taking Bradford very seriously. The Frenchman has selected his first-choice goalkeeper, first-choice back four and apart from perhaps the absent Mikel Arteta, Olivier Giroud and Theo Walcott, it's a first-choice midfield and attack!
Mannone, Jenkinson, Squillaci, Rosicky, Arteta, Oxlade-Chamberlain, Chamakh
The Gunners' two-goal man from the weekend, Arteta, drops to the bench and so does Alex Oxlade-Chamberlain.
Many would have expected Marouane Chamakh to start but Wenger has opted for Lukas Podolski and Gervinho up top.
The Bradford side is in...
Duke, Darby, McHugh, McArdle, Meredith, Thompson, Doyle, Gary Jones, Atkinson, Hanson, Wells
McLaughlin, Ravenhill, R.Jones, Connell, Hines, Turgott, Good
Bantams boss Phil Parkinson sticks with the same XI that edged out Torquay at the weekend, with Newcastle United loanee Curtis Good missing out.
Now that the teams are in, I'll quickly point you in the direction of our other live commentaries this evening. Click here to follow Barney Corkhill's coverage of the sole Premier League match of the evening between Sunderland and Reading. Alternatively, you can keep up with the other League Cup quarter-final this evening between Norwich and Villa here.
Also, if La Liga is your cup of tea then click here for Matt Law's coverage of Osasuna 0-0 Valencia.
Back to the game at Valley Parade and tonight's game is the first time the two clubs have met in the League Cup.
The previous meeting between the clubs was a Premier League game at Highbury in January 2001, which Arsenal won 2-0.
Overall, the sides have met 25 times in all competitions with Arsenal winning 11, Bradford nine and five draws.
Bradford have become the first club from the fourth tier to reach the last eight of this competition for six years.
Bradford manager Phil Parkinson tells Sky Sports News that his side have to be "disciplined" if they are to have any chance of causing an upset this evening.
His opposite number, Mr Wenger, says that he was able to select such a strong XI because their next game isn't until Monday.
This is Arsenal's 10th straight year in the last eight of this competition but we all know about their wait for a trophy. Can they end the drought this year?
Five minutes until kickoff.
Valley Parade could see it's biggest attendance for nearly 50 years tonight and the place is rocking as the players come out into the brisk West Yorkshire evening.
Victory would see Arsenal set a new outright League Cup record by qualifying for the semi-finals for the 15th time.
Arsenal get us underway.
A huge cheer goes up straight away as Arsenal hoof the ball out of play from the kickoff.
First penalty box action as Bradford almost open up a shooting opportunity. Positive start from the hosts.
Early goal for Sunderland as James McClean fires in after a corner.
Bradford's top scorer Nahki Wells almost beats Szczesny but Mike Dean had already blown for a push on Vermaelen.
Gervinho is booked for a deliberate, hand-of-God style handball.
Cazorla finds Gervinho with a ball over-the-top and the Ivorian twists and turns to try and open up a shooting opportunity but his effort is blocked.
CHANCE! Cazorla picks out an unmarked Vermaelen at the back post but the Belgian gets under his header a little, bulleting it over the bar.
Bradford go straight down the other end and Hanson almost takes the ball away from Szczesny after Mertesacker's skewed clearance.
CHANCE! Wilshere beats his man and then clips in a clever cross to Podolski who heads over from 12 yards. The German looked offside but wasn't flagged.
Ramsey presents the ball to Wells but the Bradford man can't break clear and eventually hauls down Cazorla after being dispossessed. Arsenal starting to control this now after an edgy start.
Duke picks out Wells with a kick superbly and the frontman nutmegs Vermaelen, who has to bring him down.
GOAL! BRADFORD LEAD! THOMPSON!
Wow! A shock is on the cards as Jones's free kick is flicked to the back post where number 11 Gary Thompson smacks home on the volley first time. Great finish.
"Sacked in the morning, you're getting sacked in the morning!" sing the Bradford fans to Wenger. The Gunners respond with a chorus of "There's only one Arsene Wenger!"
Goal for Norwich in the other quarter-final tonight. Steve Morison puts the Canaries one-up on Villa.
Instant equaliser for Villa! Brett Holman strokes home from the edge of the area to cancel out Morison's opener.
Some world-class first-touch football between Cazorla and Wilshere almost presents the former with a chance to lay in Podolski but Jones nips in.
Almost a second for the home side as a Jones set piece causes more problems. The captain's corner is flicked goalwards at the near post and Gibbs has to hack to safety.
Free kick for the Gunners 25 yards out as Cazorla is taken out when trying to play a one-two. Podolski likes the look of this...
Podolski takes it on but that's straight into the wall.
Great feet from the impressive Wells in the area earns Bradford a corner but there's no danger as Mertesacker heads clear. Jones pumps the ball back in and Thompson gets away a shot with his back to goal but that's easy for Szczesny.
WHEY chant the Bradford fans behind the Arsenal goal as Wilshere slices a volley on his weaker right foot miles wide.
Goal on Wearside and Sunderland have taken a 2-0 lead as Steven Fletcher marks his return to the side with a clever backheel in the area. Class finish.
SHOT! Gibbs chests a loose ball and then screams a volley goalwards that whistle's past Duke's right-hand post.
This is a worrying stat for Arsenal fans: The Gunners managed just one shot on target other than the penalties on Saturday against West Brom. Today they have none so far.
OFF THE POST! Coquelin earns some space with a step over and then fires goalwards with his left. The shot beats Duke at his near post but not the frame of the goal.
SHOT! Cazorla lets fly but it swerves inches wide of the post.
WHAT A MISS! We've got a miss of the season contender from Gervinho! The Gunners work the ball nicely to Gibbs on the left and his cross-shot should be poked home by the Ivorian from a couple of yards but somehow he only gets a whisker of a touch on it and it rolls wide!
CHANCE! So, so close to a Bradford second! Wells gets the better of Vermaelen and pokes a shot millimetres wide of the post.
Bradford 1-0 Arsenal
This is a real surprise considering how strong an XI Wenger put out. Bradford could have had one more with Well's miss at the end of the half but Arsenal should at least be on the scoresheet with that Gervinho miss!
In the Premier League, Sunderland lead Reading 2-0 with goals from James McClean and Steven Fletcher. Click here to read our half-time report.
Meanwhile, in the other quarter-final, Norwich and Villa are 1-1 at the break.
Bradford get the second half underway.
Tame start to the second period from both sides. Neither manager made any changes at the interval.
Wells has been so impressive today. First he wins a corner for the home side and then shows a great fleet of foot to win a free kick right of goal. Jones to swing in once again...
The skipper's delivery is poor though and Arsenal break. Cazorla zips a pass into Ramsey but the Welshman's shot from 16 yards is horribly sliced.
Gervinho really isn't having a good night. The Ivorian has a chance to bear down on goal but his touch lets him down and Bradford manage to clear eventually.
CHANCE! Coquelin bursts into the box and is well found by Sagna but his centre somehow manages to miss everyone in the middle.
Surely Gervinho has to come off soon? His latest error is to drag a shot horribly wide after Cazorla set him up.
First substitution for the home side as Marouane Chamakh comes on for Coquelin.
If you manually refresh the page you'll now be able to see a picture of that awful Gervinho miss. Into the final quarter of the game we go..
Arsenal make their final two changes as Tomas Rosicky takes the place of Ramsey and Alex Oxlade-Chamberlain comes on for Podolski.
SHOT! Arsenal have their first effort on target as Chamberlain gets straight into the thick of things. 20 minutes left for the Gunners to save this.
The impressive Wells is taken off for Alan Connell with just a quarter of an hour remaining.
Another Bradford substitute, Ritchie Jones, is taken out by Wilshere off the ball and that irks the young Englishman. Time running out.
The attendance at Valley Parade is confirmed as 23,971. Top effort.
SHOT! Wilshere drives at the Bantams backline and lashes low to Duke's left but that's a solid stop from the keeper.
Patient build-up rom Arsenal sees Rosicky feed Gervinho but the Ivorian's cutback is a little too far ahead of Chamberlain whose shot on-the-stretch doesn't trouble the target.
Just five minutes left!
More patience from the Gunners ends as Cazorla's shot is blocked away for a corner.
GOAL! ARSENAL EQUALISE! VERMAELEN!
They've done it, at last. Cazorla's original corner is cleared straight back to him but his second delivery is much better and picks out Vermaelen at the back post to head home from a couple of yards!
Remember, this game will go to extra time if the score stays like this at the whistle.
Four minutes added on.
The Gunners have a free kick as Meredith handles. They wouldn't, would they?
Nope. Just two minutes left.
In the other quarter-final, Villa have run away with it in the second half at Norwich and now lead 4-1.
Cazorla is tripped 28 yards from goal. This will be the last chance...
SAVES! Duke palms away Cazorla's free kick and then does even better to beat away the Spaniard's second effort after being set up by Rosicky.
Bradford 1-1 Arsenal, extra time to be played.
The first half of extra time is underway.
Arsenal goalscorer Vermaelen is booked as Bradford make a change with Blair Turgott coming on for Atkinson.
SHOTS! Oxlade-Chamberlain has a pair of shots well blocked by the Bradford defence as Arsenal begin the extra period on top.
In the Premier League tonight, Sunderland beat Reading 3-0 to move out of the drop zone. Click here to read our match report.
CHANCE! Wilshere plays a clever one-two with Chamakh but decides not to shoot when on his right foot and his dilly-dallying allows Duke to come out and thwart the England international.
SAVE! Instinctive shot from Chamberlain is well kept out by Duke.
Click here to read our report on Villa's progression to the semi-finals with an emphatic win at Norwich.
Sagna crosses deep for his fellow full back but Gibbs can't keep his header down.
CHANCE! Chamberlain is found with space in the area but his first touch is a little heavy and Duke is able to save for a corner.
Bradford 1-1 Arsenal
CLOSE! Cazorla's corner is flicked goalwards by Chamakh at the near post but his header drifts wide of the far post.
OFF THE BAR! Cazorla unleashes a rocket from 30 yards that flashes past Duke and thunders off the crossbar.
He likes a shot this boy! Cazorla lets fly once more but this time it's way off target.
Tempers are a flaring! Chamakh horribly underhits an easy pass to Chamberlain and the young winger is furious with the Moroccan.
Five minutes until penalties!
Poor, poor cross from Rosicky as Arsenal continue to camp in the Bradford half.
One minute added on.
Cazorla takes one last effort that is deflected and Duke keeps it in.
Bradford 1-1 Arsenal, we're going to penalties!
Remember, Bradford have already knocked out a Premier League club on penalties this year when they ousted Wigan. Can they do it again?!
Jones seems to have won the toss for Bradford so the home side will be shooting towards their fans.
Jones is first up for Bradford...
SCORES! Szczesny got a hand to it but couldn't stop it.
SAVED! Duke saves Cazorla's pen!
SCORES! Skipper Gary Jones with a great pen to Szczesny's right.
MISSED! Chamakh hits the right-hand post!
SAVED! Szczesny stops Darby low to his left.
SCORES! Wilshere calmly slots home to get Arsenal on the scoresheet.
SCORES! Connell sends Szczesny the wrong way.
SCORES! Oxlade-Chamberlain with a top pen to the corner. If Bradford score this, they win!
SAVED! Jones's pen is saved!
MISSES! VERMAELEN HITS THE POST! BRADFORD ARE THROUGH TO THE SEMI-FINALS!
The Belgian drags his penalty a touch and it hits the inside of the post and comes out. Cue wild celebrations from the Bantams and there's a small number of fans on the pitch.
An incredible result for League Two's Bradford. Arsenal, obviously, had the majority of the possession but many a neutral wouldn't begrudge the home side a place in the last four.
Thanks for joining Sports Mole this evening. Be sure to join us tomorrow for the quarter-final between Swansea and Middlesbrough. Until next time, goodnight!
