Jordan Spieth finished well to post a one-over 72 at the US PGA Championship, while there were conflicting fortunes for this year's other two major winners Sergio Garcia and Brooks Koepka.
Spieth, 24, triumphed at last month's Open and is aiming to become the youngest player to win a career Grand Slam by claiming victory at Quail Hollow this week.
The American world number two made an unspectacular start in the first round on Thursday, but two late birdies at least saw him recover to one over, which was five shots off leader Thorbjorn Olesen.
In warm, humid yet still conditions in Charlotte, Spieth - watched on by Olympic great Michael Phelps - started on the back nine and birdied the 15th, but he found two bunkers at the next to drop a shot.
Like several out on course, Spieth struggled as three bogeys between the first and sixth holes (10th-15th for Spieth) saw him drop to three over.
However, back-to-back gains at the seventh and eighth - the latter thanks to a brilliant approach within two feet - helped Spieth recover the situation.
How about this lag putt?!? pic.twitter.com/VmVystvH9O-- PGA Championship (@PGAChampionship) August 10, 2017
Playing alongside Spieth, Garcia found water at holes 16 and 18, leading to double bogeys either side of a bogey at 17 as he struggled through Quail Hollow notoriously difficult 'Green Mile'.
The Masters champion did birdie the fifth before posting a four-over 75, but the Spaniard has work to do just to make the weekend.
Also in that group, U.S. Open winner Koepka made a strong start with a 68, despite hitting a marshal with a tee shot during his round.
The American finished at three under, along with home-state hero Grayson Murray and Gary Woodland, to be a shot behind clubhouse leader Olesen - who had six birdies and two bogeys during his round of 67.
Meanwhile, world number one Dustin Johnson and 2015 champion Jason Day both posted 70s, while Henrik Stenson finished with a 74.
Fresh from his stunning win at the WGC-Bridgestone Invitational, Hideki Matsuyama holed three birdies to finish his round and sign for a round of 70.