Peter Uihlein holed his second shot for an eagle on the 18th hole on Saturday to grab a two-shot lead after the third round of the Alfred Dunhill Links Championship.
Having missed an eagle putt that would have given him a 59 on the Kingsbarns course on Friday, the American managed a more spectacular finish on St Andrews when his 47-yard wedge shot on the 18th found the bottom of the cup. That gave him a 7-under 65 for a 20-under total of 196.
"I wasn't quite sure what I was going to do with my second shot but it worked out well and when I saw it go in, it was pretty sweet and a nice way to sign off," Uihlein said.
Ernie Els shot a 64, also on St Andrews, to be among six players to sit two shots back. The group also included Martin Kaymer (63) and Joost Luiten (68).
England's Paul Casey equalled the Old Course record with a 10-under 62 but finds himself back in a share of 25th place, seven shots back.
Uihlein's putt for 59 on Friday came up just inches wide, leaving him a tap-in for a 60 that had two shots behind overnight leader Tom Lewis. However, Lewis only managed a 73 on Carnoustie on Saturday to drop down the leaderboard.
Uihlein was playing on the Old Course for the first time, and is looking forward to returning on Sunday.
"It's always tough backing up after shooting a low round like I had yesterday at Kingsbarns but I managed to get off to a great start today with four birdies in a row from the fifth and then to eagle the last was a real bonus," Uihlein said.
"And to play the Old Course for a first time was awesome and it's one of the best, if not the best golf course in the world."
Uihlein is looking for his second European Tour victory of the season after winning the Madeira Open, having managed three top-10 finishes since then.
However, there are 16 players within five shots of the lead - with Els among those who have a lot more experience playing at St Andrews.
"I am in a great position but then there are a lot of guys up there and we'll see what happens on the back nine," Els said.