Rory McIlroy was made to rue missed opportunities and a wayward driving display after his opening round at the PGA Championship.
The world number three carded a level par 70 at Harding Park and finished up five shots behind leader Jason Day after the morning session.
His playing partner Tiger Woods and Open champion Shane Lowry both finished at two under par.
McIlroy had it all to do when he found himself two over par after five holes.
Starting at the tenth, McIlroy's opening birdie was quickly surrendered with three consecutive drop shots from holes 12 to 14.
A run of three birdies in four holes around the turn proved that a challenge is far from beyond him this week.
But, as he admitted after his round, an improvement off the tee will be required. He hit just six of 14 fairways - wayward drives the reason for three of his four drop-shots and aso ensuring he couldn't attack pins tucked in tricky locations.
"It was there for the taking today," said a rueful McIlroy. "I feel like I definitely could have been a few shots lower but I sort of ground it out and with how I hit it on the back nine, even par actually wasn't too bad.
"I didn't hit fairways, and then from there, the way that the pins were tucked, I was just trying to play to the front of the greens and two-putt from 40 feet and move on to the next hole.
"I need to hit a few more fairways tomorrow to try to attack some pins and get it closer, and not leave myself four and five footers for par all day."
At the top of the leaderboard, Day is being chased by a pack of players on four under, including Scottie Scheffler, Xander Schauffele, Bud Cauley, Zach Johnson, Justin Rose, Brendan Steele and another former PGA champion Martin Kaymer.
Also lurking ominously at four under as he always does at the big events, two-time defending champion Brooks Koepka, aiming to become only the third golfer to win the same Major for three consecutive years.
Offaly native Shane Lowry was conspicuous by his absence from the TV coverage, with only his tap-in par putt on the final hole shown to viewers.
What they didn't see was a round that included three birdies and just one bogey, with his 30 putts, including a three-roll bogey at the 14th, his main bone of contention after he finished out his two under par 68.
"I missed quite a few chances in the middle of the round, but I thought I was hitting good putts, burning the edge a little bit. It was getting frustrating, but it was nice to birdie the seventh, my 16th and get it in at two under."