Kevin Kisner held a one-stroke lead over Hideki Matsuyama and Chris Stroud midway through their third rounds at the US PGA Championship as players struggled to get moving.
A surprise co-leader through 36 holes, Kisner was one under through nine in his third round at Quail Hollow and sat clear of the field at nine under overall.
The American, without a top-10 finish in his major career, showed no signs of nerves and had other opportunities in fine conditions.
Matsuyama, who shot a stunning seven-under 64 in the second round, hit just two fairways on the front nine but was even for the day to be a shot back.
The other member of the final group - Jason Day - was one over in his third round, leaving him four off the pace.
However, the unheralded Stroud moved into a tie for second with Matsuyama after turning in two under.
Matsuyama, coming off a bogey-free round, dropped a shot at the first – a hole at which no birdies were made in the third round – missing a left-to-right six-footer after finding the left greenside bunker.
Day joined him in a tie for second at the next hole, a brilliant approach to within four feet seeing him birdie as Kisner and Matsuyama missed chances.
Kisner created birdie opportunities on each of the first three holes, and his perfect record from inside 10 feet at this tournament came to an end when he missed from seven at the third.
Day seemingly misread a four-foot birdie putt at the fifth before opportunities predictably arrived at the par-five seventh.
Matsuyama tapped in for birdie but Kisner, who almost found the water with his second, also picked up a shot to remain one stroke clear.
Day had eagled the hole the previous two days but had to settle for par after three-putting and the Australian then bogeyed the ninth.
Louis Oosthuizen was at five under with Day, while Rickie Fowler and Justin Thomas were a shot further back.
Spaniard Jon Rahm briefly made a move on Saturday and was five under through 14 before going five over on his final four holes.
Jordan Spieth's bid for a career Grand Slam is set to have to wait, the world number two shooting a 71 to reach the clubhouse at three over.
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