Sean Crocker produced two brilliant bursts of scoring as he fired a course-record 63 to lead by a single shot on the opening day of the 2022 Hero Open at Fairmont St Andrews.
The 25-year-old American picked up six shots in five holes on the front nine after going birdie-birdie-birdie-eagle-birdie from the third.
And after dropping his only shot of the day at the tenth, he made four birdies in his next five holes to get to nine under par and stand alone at the top of the leaderboard.
After a day of low scoring, Frenchman Romain Langasque, English duo Ben Stow and Ashley Chesters, Swede Jens Dantorp and Spaniard Adrian Otaegui were in a tie for second on eight under, one ahead of the group containing home favourites David Law and Connor Syme.
Crocker opened his round with pars at the first and second before picking up back-to-back birdies from close range on the third and fourth.
He made it three in a row with a lengthy birdie putt from the fringe of the fifth green before firing an eagle at the sixth from 14 feet to jump to five under.
A birdie from nine feet followed on the seventh before Crocker carded his first bogey of the day at the tenth.
But he bounced back in style, reeling off birdies at the 11th and 12th to grab a share of the lead.
He sent his tee-shot into the thick rough at the 13th but escaped with a par there before holing from 17 feet on the 14th to take the outright lead.
A stunning up-and-down from an awkward spot in a bunker saw the American make another birdie at the 15th before three closing pars rounded off a brilliant 63, which is Crocker's lowest-ever round on the DP World Tour.
That milestone comes in the same season as a long run of missed cuts at the beginning of the year which Crocker described as one of the toughest things he has been through.
Since then, Crocker has enjoyed strong finishes at the Soudal Open and Barracuda Championship in recent months, and he admitted his experiences this year taught him a lot.
He said: "Nine missed cuts. Mentally that was the toughest thing I’ve gone through so far.
"People speak about the mental side of sport but that’s probably the darkest I’ve been in life on a golf course.
"It’s the first time I’ve had bad things happen to me on the golf course. And it’s just a case of having to grow up.
"Just said to myself, 'okay, you’ve been lucky to play good golf your whole life and now you’re going to get a taste of what this game is really like'.
"You just realise how hard this game is, and I realise that I can hit bad shots; I can do all the work and I can still hit bad shots.
"There’s no point in getting upset.
"Mentally it helped me out a lot. It showed me a lot of bad places on a golf course but it showed me, it opened my eyes to the game of golf."
Speaking about Thursday's opening round, Crocker said: "That was fun. I'll be honest, I don't get too many days like that on the greens.
"It's fun making putts, I'll definitely say that, because I'm not used to it as much as some of these guys."
