Adam Scott has finished the opening round of the PGA Championship in sixth spot, dropping from second with a disappointing final hole on the Oak Hill course.
Hours after early starter Jason Day came crashing back to earth with a 6-over-par 76, Scott joined clubhouse leader Bryson DeChambeau in top spot at 4-under.
Scott carded three birdies on the front nine, with a bogey on the ninth his only blemish, but he immediately got that stroke back on 10 and joined DeChambeau in the lead with another birdie on the 14th.
He then missed a golden opportunity to take the outright lead with a 5-foot putt for birdie on 16, but missed just left, allowing American Eric Cole to move to number one on the leaderboard with a birdie on his 13th.
Scott continued apace with three straight par holes from 15 to 17 before things went south on the par-four 18th.
In fading light due to a frost-delayed start, Scott landed his second shot in a greenside bunker and badly miscued his downhill chip, failing to get out of the sand.
The 42-year-old then left his fourth shot well short of the hole and just missed the long bogey shot, two-putting for a double to fall from one shot off the lead and into a tie for sixth, three strokes back.
Some groups, including that of leader Cole, will have to return early on day two to finish their opening rounds in Rochester.
Day was one of the first out on course when play was finally allowed to go ahead, just a few days after scoring his first win since 2018 at the Byron Nelson event with a score of 23-under, seemingly giving him form heading into the second major of the year.
But it all unravelled in upstate New York, with the 2015 PGA winner carding an opening-round 6-over-par 76, including four bogeys and a double.
Compatriots Cam Davis (1-over), Cameron Smith (2-over), Min-woo Lee (3-over) and Lucas Herbert (5-over) also endured rough starts, while David Micheluzzi was 7-over through 15 and set to finish his round on day two.
The Aussies were not the only ones who struggled on day one at Oak Hill, with fellow major winners Rory McIlroy (1-over), Collin Morikawa (1-over), Shane Lowry (3-over) and Jordan Spieth (3-over) among those on the wrong side of par.
Things did not start too badly for Day, with pars through his first four holes, after starting on the 10th, but it came unstuck when he lost his ball off the tee box on 14.
He found the bunker with his do-over, chipped onto the green with his fourth shot, and two-putted for a double bogey.
Bogeys on 16, three, eight and nine followed as he tumbled towards the back of the pack.
Smith and Lee had more mixed rounds, with Smith carding three birdies and five bogeys, while Lee had a two-birdie, five-bogey round.
