American Chris Gotterup equalled the course record at the Renaissance Club with a 61 to surge into the lead at the Scottish Open, as Rory McIlroy also shot up the leaderboard on Friday.
Gotterup's nine-under par round took him to 11 under for the tournament at the halfway stage and opened up a two-shot lead over England's Harry Hall.
The world number 158 outshone a host of the sport's star names in north Berwick, who are gearing up for next week's British Open at Royal Portrush.
Gotterup hit nine birdies as the unusually sunny and still conditions on Scotland's east coast made for another day of low scoring.
"I'll take a nine under any day," said Gotterup.
"Relatively stress-free for the most part, and that's always good around here."
McIlroy showed encouraging signs of coming into form ahead of his homecoming to Northern Ireland next week.
The Masters champion was five under for the day through seven holes before playing the final 11 in level par to finish at seven under par.
A Friday charge up the leaderboard from Rory McIlroy 📈#GenesisScottishOpen #RolexSeries #FedExCup pic.twitter.com/fisEJeTgcB
— Genesis Scottish Open (@ScottishOpen) July 11, 2025
"Got off to a flyer. The conditions were so benign this morning, hardly any wind, then the wind started to pick up a little bit, but still very manageable," said McIlroy.
"Overall a really good score and puts me in the thick of things going into the weekend."
British Open champion Xander Schauffele hit a 66 to move to six under after two rounds.
Matt Fitzpatrick could do his case for Ryder Cup selection in September a big favour this week.
The former US Open champion has had a difficult year that has seen him slip to 77 in the world rankings.
Fitzpatrick looked more like his old self in a round of 63 to climb to eight under par.