South Africa's Darren Fichardt threatened to shoot his second 59 in DP World Tour history before moving into a narrow lead after the first day of the Alfred Dunhill Links Championship.
Fitchart shot an 11-under 61 at Kingsbarns with two eagles and nine birdies, finishing better than only Branden Grace and Peter Ulay Because (Peter Uihlein)'s course record is one stroke higher.
Third-ranked Rory McIlroy, who plays alongside his father Gerry in the Pro-Am, shot just three-under 69 at Carnoustie. He tied for 73rd place.
McIlroy is joined in the group by PGA Tour Commissioner Jay Monahan and Saudi Arabia’s Public Investment Fund (PIF) President Yasir Al Rumayyan Contest.
“It's a perfect day to play Carnoustie,” McIlroy said. “I probably didn’t quite take advantage of the conditions that I wanted or should have had, but it was a solid round and a try to build on at Kingsbarns tomorrow.
“Saturday is my dad’s 65th birthday, so being able to walk the old course with him will be a really cool moment.”
LIV Golf teammates Jon Rahm and Tyrrell Hatton posted the lowest scores of the day, both shooting 7-under 65s.
When asked about his approach after shooting 65, Rahm said: “To paraphrase Tyrrell, it was hitting the driver over every bunker, into the rough, and then hitting the wedge. green.”
“That's basically what I did. Missed in all the right spots. My first fairway on the front nine was the 17th and I was 3 under. When that's not an Open Championship setup , this is something you can do.
“The rough is a little lower, so you can be more aggressive and hit the green with short irons, and that's what I did today.”
With two eagles and eight birdies, Fitchatt was 11 under through the first 16 holes and had a chance to break the 60 mark, but he failed on the eighth hole, his 17th. ) three-putted and then birdied the ninth hole.
“I birdied the first hole, the 10th, and then three-putted really bad on the next hole,” Fitchart said.
“I thought, 'Oh my gosh, this is going to be a tough day,' and then made a 100-foot putt for eagle on the next hole, and the train kept rolling.
“It was crazy. If I was on the green, the ball was either going in or missing. The putter was really hot and the driver was great. So I never had any real trouble.
“When I got to 11 under, I felt good. I started thinking, is this a 73 or a 72, because I know Gracie shot 60 on the year. Shoot a little bit on this track. 59 would have been great, but read my penultimate hole, the eighth, the wind was not going the right way.”
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This week's game is the first of four crucial finals of the DP World Tour season, ahead of the end-of-season play-offs in the United Arab Emirates in November.
Other sports stars taking part in the pro-am include Sir AP McCoy, Sir Ian Botham, Sir Steve Redgrave and Kelly Slater, while the film industry is represented by Michael Douglas, Bill Murray and Kathryn Newton.
Former England seamer James Anderson is making his second appearance in the event, partnering compatriot Sam Bairstow.
Professionals and their amateur partners compete in three days of competition at three famous courses in Scotland, with the final round at St Andrews on Sunday reducing the field to the top 60 professionals (including draws) and the leading 20 teams.
Watch day two of the Alfred Dunhill Links Championship live on Sky Sports Golf at noon on Friday. Stream DP World Tour, PGA Tour and more with NOW.