A badly-timed weather delay and even a bizarre sliding tackle from a security guard failed to prevent Tiger Woods from surging into contention for a 15th major title on a sensational second day of the 83rd Masters.

Woods had just recorded the first birdie of the day on the daunting 11th hole and fired a superb tee shot to five feet on the 12th when the siren sounded to suspend play due to the threat of lightning at Augusta National.

After a delay of around 30 minutes play was able to resume and Woods missed the birdie attempt, but did pick up a shot on the 14th in extraordinary circumstances a few minutes later.

For the second day running Woods pulled off a superb recovery shot from the trees on the par four, only for a security guard to run in to try to control the crowd, slip on the wet ground and slide knee-first into Woods's right ankle.

Woods limped away grimacing in pain but there appeared to be no lasting damage and after holing from 15 feet, the 43-year-old also converted from twice the distance on the par-five 15th.

Further good chances went begging on the 17th and 18th but a 68 left Woods just one shot off the lead shared by Francesco Molinari, Jason Day, Brooks Koepka, Adam Scott and Louis Oosthuizen, all current or former major champions.

Former world number one Dustin Johnson, South African debutant Jason Harding and Xander Schauffele were alongside Woods on six under, Schauffele carding the lowest score of the week with a superb 65.

Ryder Cup team-mates Ian Poulter and Jon Rahm were two shots off the pace on five under, while Rory McIlroy kept his hopes of the career grand slam alive with a 71 to finish level par.

Molinari had to wear a white boilersuit on his first visit to the Masters as caddie for his brother Edoardo, but put himself in position to leave this time with a coveted green jacket thanks to a flawless 67.

"I didn't learn much about the course because we were going sideways most of the time," Molinari joked in reference to Edoardo shooting rounds of 80 and 77 to comfortably miss the cut.

Molinari made his debut as a player in 2010 and recorded his best finish to date with a tie for 19th in 2012, but came into the event on the back of a stellar 12 months.

The 36-year-old has won four times since last year's Masters, including the Open Championship at Carnoustie, while he also became the first European player to earn a perfect 5-0 record in the Ryder Cup in Paris.

Beginning the day four shots off the lead, Molinari birdied the third, eighth and ninth to reach the turn in 33 and picked up further shots on the 12th and 15th before a superb two-putt from 75 feet for par on the last.

"It was good, pretty solid, not many mistakes and when I missed greens I missed them on the good side, leaving myself pretty easy up and downs so all in all a very good day," Molinari said.

"Now I'm just going to rest. The game is in good shape so I don't think I can gain much from hitting balls. Just get as much energy as possible for the weekend. There's going to be a lot of players in the mix and a very long way to go."

Poulter enjoyed a massive slice of luck when his approach to the 13th stuck in the bank of Rae's Creek and allowed him to chip and putt for an unlikely birdie, but added: "I'm a little frustrated with a couple of missed opportunities towards the end there.

"But it's on the board and I am in position and it's going to be a good weekend. There's a long way to go and if you put yourself in position with nine to go the course opens up. As long as I am there or thereabouts and try to be super aggressive who knows what can happen."

World number one Justin Rose missed the cut for the first time in 14 appearances after a 73, but Jordan Spieth recovered from an opening 75 to make the weekend thanks to a 68.