Justin Rose (5/1 US Masters outright) overcame a poor start to his second round to maintain his place at the top of the Masters leaderboard, but has seen his advantage cut to just one shot.
The Englishman, a two-time runner-up at Augusta, started the day with a four-shot advantage but quickly saw that evaporate after four bogeys in his first seven holes.
The former US Open champion was able to steady the ship before fighting back, making three birdies in four holes from the 13th onwards as he eventually signed for a level-par 72 to stay at seven-under.
“The finger was moving towards the panic button, it was a poor start for sure,” Rose told BBC Sport. “I was really pleased to turn it around and made some great swings around Amen Corner. I got aggressive on the 13th tee and felt that was the turning point.
“Rarely do you put together a great round and back it up with another the following day. My intention was to play free and I did that.”
Having been one of only 12 players to break par on day one, Rose was unable to take advantage of the more favourable scoring conditions on Friday which allowed the chasing pack to close the gap.
A shot further back is Jordan Spieth, who is now the 19/5 favourite with Betfred to win the Masters after carding a 68. The 2015 Green Jacket recipient is joined in a tie for fourth by Australian Marc Leishmann.
Justin Thomas (9/2 Masters outright) had looked on course to join Spieth and Leishmann on five-under, only for a dropped shot on the final hole to scupper his chances.
Thomas, who could replace Dustin Johnson as world No.1 should he win the Masters, is instead part of a six-way tie for sixth, alongside Tony Finau (14/1) after he carded the best score of the second round, a six-under 66.
Further down the leaderboard, Bryson DeChambeau bounced back from his poor first round to shot a 67 to move onto 1-under, one shot better off than English duo Matthew Fitzpatrick and Tommy Fleetwood.
However, it wasn’t such a good day for defending champion Dustin Johnson as he joined Rory McIlroy in missing the cut, finishing at five-over less than four months after winning the Masters with a record score of 20-under.