Sergio Garcia blundered with a double bogey at the infamous short 17th to relinquish the lead at the halfway stage of the Players' Championship.
Garcia had regained his overnight lead but took five at the tricky island green on the way to 73 for five under, one stroke behind leader Kenny Perry.
German veteran Bernhard Langer, 50, shot a 67 to share second with Garcia and American Paul Goydos at Sawgrass.
Ernie Els, Phil Mickelson and England's Ian Poulter ended on one under.
Poulter dropped four shots in the final six holes for a 74 and said he was "extremely disappointed".
Luke Donald was the next best Briton but he had to work hard to stay in the tournament, adding a 72 to his opening 75 for three over.
606: DEBATE
"Yesterday was definitely worse than today," he said. "I only hit four fairways and seven greens (in regulation) yesterday. Today I hit a lot more greens but I'm still making too many mistakes.
"I'm working really hard and waiting for something to click, but still struggling a bit."
The star of round two was definitely Langer, who made the best score of the day despite struggling physically.
"I was a mess and contemplating withdrawing from the tournament Wednesday evening," he said.
"I thought if I can get through (the first round) I might improve every day, and that's exactly what happened, so I'm thrilled to be here, to be swinging and with the score as well."
Langer made his move early with four birdies and an eagle in the first eight holes.
"I was six under after eight, playing close to perfection," he said.
"I hit the ball well and putted well, did everything right. It was probably the best start to any tournament I've played in my career."
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