World number one Scottie Scheffler, who began the day in Kentucky three shots off the lead but having shot even par or better in each of his last 42 official rounds on the PGA Tour, fell back with a two-over-par 73 that left him eight shots adrift.
The reigning Masters champion, chasing a fifth win in six starts, was playing a day after being arrested on four counts, including second-degree assault of a police officer, after what he said called a "big misunderstanding" outside Valhalla Golf Club.
Xander Schauffele and Collin Morikawa held a two-way share of the PGA Championship lead after the third round at Valhalla Golf Club, while Shane Lowry made an epic charge up a jam-packed leaderboard.
Schauffele, who held the solo lead after the first two rounds, birdied the final two holes at Valhalla en route to a three-under-par 68 that left him at 15 under on the week and level with twice major winner Morikawa (67).
Six players are within two strokes of the leaders entering the final round, including Sahith Theegala (67), who made five back-nine birdies and sits alone in third place.
Former Open Championship winner Lowry, whose 62 matched the lowest score in major championship history, LIV Golf's Bryson DeChambeau (67), who eagled the final hole, and Viktor Hovland (66) are sitting two shots back.
Schauffele, in search of his first major, was fresh off draining a 29-foot birdie putt at the 14th to open a two-shot cushion before encountering trouble at the par-four 15th where his second shot found the long rough, leading to a double-bogey.
Moments later, Morikawa's birdie putt from five feet at the same hole circled right around the cup before dropping in and giving him a one-shot lead.
But Schauffele refused to back down and went on to tap in for birdie at the par-four 17th after his brilliant approach shot from 141 yards settled two feet from the cup before he and Morikawa both birdied the last.
Englishman Justin Rose, who has recorded five consecutive top-15 finishes at the PGA Championship, also moved into the mix with five front-nine birdies en route to a 64 that left him three shots back of the leaders and in a share of seventh place with Robert MacIntyre (66).
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Reuters