Hideki Matsuyama moved into the outright lead in the final round of the US PGA Championship after Kevin Kisner faltered on one of the easiest holes at Quail Hollow on Sunday.
Matsuyama, looking to become the first Japanese player to win a major, got through the front nine in a one-under 34 to be seven under overall.
The world number three made back-to-back birdies at six and seven and held a slender one-stroke lead over Kisner, who was one over for his round, Justin Thomas and Chris Stroud.
Kisner had once again appeared to be cruising around in hot and humid conditions, but he found water at the seventh and made bogey. The American had made par on the first six holes before his error.
Francesco Molinari (three under through 12) and Patrick Reed (three under through 10) surged into contention at five under overall, the same score as Louis Oosthuizen.
Rickie Fowler sat at four under for the day through 14 and outright eighth.
Matsuyama should have made birdie on one - he missed a four-footer - but instead dropped a shot at the second after a wayward tee shot.
Stroud bogeyed the first and Thomas did likewise, although the latter bounced back with a birdie at the second as Kisner was left two clear.
As he had been the case for most of the week, Kisner was staying consistent and he managed a par save at five after finding the bunker.
A fine tee shot at six saw Matsuyama birdie from nine feet to once again join Stroud in a tie for second a shot back. Stroud then slipped back after bogeying the same hole, having found the bunker off the tee.
Taking advantage of the par-five seventh was always going to be crucial, Matsuyama birdieing after a monster eagle putt left him with five feet.
Matsuyama birdies back-to-back to take a share of the lead.-- PGA Championship (@PGAChampionship) August 13, 2017
Watch now on CBS! pic.twitter.com/LZHtndhCoI
But the same hole would prove costly for Kisner, who found the water with his second shot - as he almost did on Saturday - to make bogey and fall out of the lead.
Kisner managed a par save at eight as Stroud birdied, while Thomas holed a 36-footer for birdie on nine, the leaderboard becoming congested ahead of a thrilling conclusion to the year's final major.