Overnight leader Justin Rose was faltering through nine holes of his second round at the Masters on Friday.
The Englishman made light of tricky scoring conditions to shoot a stunning seven-under-par 65 in round one, during which he picked up nine strokes from the eighth hole having played the first seven at two over.
But after starting bogey-birdie on Friday, Rose dropped three more shots before the turn and was at four under for the tournament midway through his second round.
Bernd Wiesberger was only one shot back having gone through 14 holes at five under for the day, while Hideki Matsuyama and Brian Harman were the same score but yet to begin round two.
Jordan Spieth was only two behind through four holes of his second round, with Marc Leishman among a cluster of players also at -2.
Tommy Fleetwood, Tony Finau and Cameron Smith were all playing the round at three under as the leaderboard bunched up early on Friday, while Justin Thomas was back at level par overall.
The likes of Jon Rahm (E), Dustin Johnson (+2) and Rory McIlroy (+4) are scheduled to tee off later on Friday.