Cameron Tringale is the halfway leader at the 2022 Genesis Scottish Open after battling his way to a second-round 72 to head into the weekend on seven under par.
Tringale's fellow Americans Gary Woodland and Doug Ghim are his closest challengers, three shots back after posting rounds of 72 and 69 respectively.
Tringale began the day three clear of Woodland after producing a course-record-equalling 61 at The Renaissance Club on Thursday, and stretched his advantage after starting his second round at the tenth, picking up shots on the 11th after an approach to four feet and the short 12th by sinking a 26-foot birdie putt.
By the 13th, he was bogey-free for the first 22 holes of his tournament, with 11 pars and 11 birdies, but after a first bogey arrived at the 14th, when he took three from the fringe at the front of the par three before bouncing back with a birdie on the 15th, four dropped shots in a row followed from the 16th.
He birdied the fourth but gave it back at the tricky sixth before parring his final three holes on a much tougher day than Thursday, with the wind continuing to blow in North Berwick.
A four-strong group sit one shot further behind Woodland and Ghim, and leader Tringale will be looking over his shoulder at the big names waiting to pounce.
Matt Fitzpatrick is among them. The U.S. Open Champion was flawless until bogeys at his last two holes but he signed for a 66.
Xander Schauffele went one better and his 65 was the lowest round of the day. Joining Fitzpatrick and Schauffele on three under are Jordan Smith - who bagged a new car each for him and his caddie after an ace at the 17th - and Kurt Kitayama.
Tyrrell Hatton was on two under alongside Rafa Cabrera Bello, Rickie Fowler, Rasmus Højgaard and Joaquin Niemann.
Tringale, who is searching for his maiden victory on both the DP World Tour and PGA TOUR in this co-sanctioned tournament, said: "It was definitely more difficult for me today.
"Yesterday, it seemed pretty easy, and today, it seemed like every hole was a grind to make par.
"So anyway, happy to be done and happy to be off the course and get some rest.
"I just want to keep going out and trying to play the best I can and hopefully get a good low one in tomorrow.
"I mean, the course I think is still gettable, honestly, even in the wind, I just need to play the par-fives a little better, and you know, work on those into-the-wind shots and I should be all right."
Woodland, who mixed six bogeys with four birdies on Friday, said: "It was a tough day. A lot of crosswinds.
"I didn't drive it as well as I did yesterday and that was really the difference. Outside of that, I played well.
"I hit a lot of good putts that didn't go in."
Ghim fired four birdies and three bogeys in testing afternoon conditions and said: "Anything under par today in the afternoon was really good and we had some tough holes coming in.
"To get out there and be at four under is definitely something that I'm very pleased with.
"I was just telling my caddie that I think this is my favourite place in the world to play golf.
"It makes you think. There are some shots that you have to play like in America, and some shots that I would never consider playing back there.
"I get to use my knowledge of how I normally would play and learn some new things and new horizons in my game, and I always feel like I leave Scotland a better player.
"I'm just hoping to keep the good play and hopefully stay here for one more week."