St Andrews - England's Tyrrell Hatton equalled the St. Andrews Old Course record with a blistering 10-under par 62 to move three shots clear on day three of the Alfred Dunhill Links Championship.
Hatton, who turns 25 next Friday, capped his round of 10 birdies with three in succession from his eighth hole and then another pair on his closing two to move to 17-under par.
His effort over the course, that also hosted last year's British Open, matched a 62 recorded by three others including compatriot Paul Casey in the 2013 event.
Hatton's effort equalled his European Tour best after recording a similar 62 during last year's European Masters but on a par-70 host course in Switzerland.
"This round is clearly the best round I've ever had," he said.
"I've never actually got to double digits under par before, so I'm very pleased with that.
"The goal now is to get a win. But then it's been a really consistent year, and it would be nice to have a good finish."
The current world number 53 has enjoyed six top-10s in his 17 European Tour events this year, capped by being runner-up in July's Scottish Open and then finishing in a tie for fifth a week later in his very first British Open appearance.
But while Hatton was working his way to the top of the leaderboard in the $5 million event, a lot of attention was on his amateur playing partner, Jamie Doran, the Northern Ireland-born actor and star of "50 Shades of Grey".
"It's good fun playing alongside Jamie Doran as there were big crowds out there all three days, so it's all been good fun," said Hatton.
Fellow Englishman Ross Fisher let slip his overnight one-stroke advantage in adding a 69 at Carnoustie, one of the three host venues, to move to 14-under par.
"It was a decent round of golf but then you never know what you are going to get when you turn up to Carnoustie," he said.
"We were all hoping for 'Car-nicely' and not 'Car-nasty'. We got 'Car-nicely' as it was a beautiful day to play the place."
South African Richard Sterne (65) and Sweden's Joakim Lagergren (69), and both competing at St. Andrews, share third place on 13-under par.
The German pair of double Major winning Martin Kaymer (65) and Florian Fritsch (65) are next best in fifth spot at 12-under par.
"I was quite a few shots behind at the start of the day, so the main goal was to make the cut with my father as my amateur partner," said 2010 winner Kaymer.
"For myself, I'm very pleased the way I played today and if I'm four or five shots behind, it's fine. It's going to be an interesting Sunday, any ways."
However, there will be no Sunday play for Masters champion Danny Willett who continued to struggle signing for a third day 76 at St. Andrews and slumping to a share of 143rd place at four over par.
Joining him in missing the cut was Ryder Cup teammate, Lee Westwood who improved with a 69 after Friday's shock 82 to end his challenge at 10-over par.