Daniel Berger made nine birdies in a flawless round as he stormed to an impressive three-stroke lead on day one of the Arnold Palmer Invitational in Florida.
The 32-year-old American – a four-time winner on the PGA Tour, whose last triumph came five years ago at Pebble Beach – picked up three birdies on the front nine, but caught fire with six coming in.
The early pace-setter rolled in three straight birdies starting on the 10th, before adding another with an 11-foot putt at the par-three 14th, and two more birdies on the 16th and 18th for a bogey-free round of 63.
Berger sits three clear of recent Pebble Beach champion Collin Morikawa and Sweden's Ludvig Aberg.
World No 1 Scottie Scheffler shot 70, while Rory McIlroy – gearing up to defend his Masters title next month – finished on even-par after an erratic round featuring five birdies and a double bogey.
Berger, who missed three months of golf last fall after breaking the ring finger on his right hand on a shot at the BMW Championship in August, said "the biggest thing for me is just getting in a bit of a rhythm."
"When you come back you're just kind of getting back into the flow of things and getting into your routine," he said.
"I've really played not really that poorly, and just haven't had the results," he added.
The broken finger was just the latest injury setback for Berger, who missed 10 months over 2022 and 2023 with back issues and struggled for consistency when he returned in 2024.
The native Floridian predicted conditions would be "incredibly difficult and challenging" for the rest of the week at the Bay Hill Club & Lodge in Orlando.
"You can already see the greens are like white. So a little bit of wind, a little bit less moisture, and it's just going to be like a US Open," he said.
"I think when you come to Bay Hill to play this event you know what you're getting, and so it doesn't shock me. You're ready for it."
'UNBELIEVABLE'
Morikawa, a two-time major winner who ended a two-year title drought with a victory at Pebble Beach in February, surged late for his six-under round.
He hit a flush seven-iron into the par-five 16th and holed a 15-foot eagle putt before birdies at 17 and 18 – where he drained a 27-foot putt.
"I hit three 7-irons to finish the day, three birdies, I'll take it," said Morikawa, who finished runner-up at last year's Arnold Palmer Invitational, despite leading eventual winner Russell Henley by three strokes with five holes to play.
Aberg was delighted with his 66 in swirling winds on a notoriously tricky course, describing leader Berger's 63 as "quite unbelievable."
"I was not trying to be overly aggressive. I wasn't trying to be overly conservative either, but it was tricky with the crosswind and kind of going back and forth," he said.
"Overall really pleased with the score."
Scheffler was left to rue "a couple mistakes that I shouldn't have made" in his two-under effort, which also included three birdies.
"Anything under par on this golf course is a decent score," added the American, who has switched to a new driver this week in a quest for more accuracy off the tee.
McIlroy found the water with his approach iron on the par-four 13th. Forced to take a drop, he again missed the green and had to settle for a double bogey.
His turbulent round also included bogeys on the fifth and 18th.