Top-ranked defending champion Scottie Scheffler tumbled from a share of the lead with three bogeys in his first four holes in Friday's second round of the PGA Championship.
Cold weather and gusting winds at Aronimink plus its sloping greens battered the world's top golfers, back-nine starter Scheffler missing his first six fairways after hitting 13 of 14 on day one.
Scheffler had been among seven players who shared the 18-hole lead on three-under, the most co-leaders in a major since 1989.
Australian Min Woo Lee, Japan's Ryo Hisatsune, South African Aldrich Potgieter and Germany's Stephan Jaeger were co-leaders with afternoon start times Friday.
Four-time major winner Scheffler joined American Alex Smalley and two-time major winner Martin Kaymer of Germany as morning starters among the co-leaders.
Kaymer made bogeys on five of the first seven holes to stumble back.
Smalley grinded out six pars on the back nine to keep his share of the lead, the most spectacular on a 19-foot putt at the 15th.
Then there was Scheffler, who found thick left rough off the 10th tee, plunked his approach short of the green, punched to 19 feet then missed his par putt.
He had a similar path to bogey at 12, missing a 10-footer for par, and added a three-putt bogey at 13 to reach level par.
Fellow American Patrick Reed, the 2018 Masters winner, made a five-foot birdie putt at the fourth to briefly share the lead on three-under.
Two holes later, Reed made a three-putt bogey, becoming the last player to take his first bogey of the week.
Japan's Hideki Matsuyama, the 2021 Masters winner, joined Reed on two-under with birdies at the 13th on a 23-foot putt from just off the green and the third from eight feet in a bogey-free start.
England's Justin Rose opened with a double bogey at the 10th and added another at 14, soaring to four-over, two beyond the projected cut line.
Six-time major winner Rory McIlroy, the reigning Masters champion, spent hours on the practice range Thursday evening after spraying tee shots in an opening-round 74, making bogeys on five of the last six holes.
Not since Payne Stewart in 1979 has a PGA winner opened on 74.
Joining McIlroy with an afternoon start will be a one-under pack including five-time major winner Brooks Koepka, two-time major winner Jon Rahm and three-time major winner Jordan Spieth with two-time major winner Xander Schauffele on two-under.
Spieth would complete a career Grand Slam with a victory while Rahm would become the first Spaniard to win the PGA title.
Also starting late is two-time major winner Bryson DeChambeau, who fired an opening 76.