Ludvig Åberg carded a second consecutive round of 64 to take a one-shot lead into the weekend at the Genesis Scottish Open.
The Swede went bogey-free on day two at The Renaissance Club to get to 12 under as he looks for a maiden Rolex Series title to continue his remarkable rise in the game.
He was sitting outside the top 300 on the Official World Golf Ranking when he missed the cut here in just his fifth professional start 12 months ago but in the year since he has won maiden titles on the DP World Tour and PGA TOUR, played on a victorious European Ryder Cup team, finished second at the Masters Tournament on his Major debut and risen to fourth in the world.
The 24-year-old is unlikely to have it all his own way over the final 36 holes in East Lothian, however, with a stellar field assembled for an event co-sanctioned by the PGA TOUR.
Frenchman Antoine Rozner stayed bogey-free for the week with a 64 of his own to sit at 11 under, a shot clear of Italian Matteo Manassero, who carded a 63, and South Korea's Sungjae Im who carded a 67.
Defending champion Rory McIlroy, American pair Collin Morikawa and Sahith Theegala, Spaniard Alejandro del Rey, Dane Rasmus Højgaard and Swede Alex Noren were then at nine under.
There are three places available at next week's Open Championship in Scotland and Rozner, Del Rey and Noren would take them as it stands as the leading three players not currently exempt.
Åberg carded six birdies on day two and felt his mentality was the key on the links-style test of Renaissance.
"It's been very nice," he said. "I felt like we've had a very good game plan and executed the shots.
"We try not to force anything. We try to have a lot of acceptance when we play and make sure that we put good swings on it and give ourselves plenty of chances, which I felt like we've done very well.
"There's what, 150-something players in the field? No one is going to play perfect golf for 72 holes.
"I think it's going to happen to everyone at some point and whenever that happens you've just got to try to deal with it the best you can.
"All I can do is try to put good swings on it and then hopefully the decision that we've made is the right one and try to hit it again when we find it."
Starting on the tenth, Åberg left himself a tap-in at the 11th and put a tee-shot to eight feet at the par-three 14th.
A fantastic up-and-down from the rough at the par-five 16th was followed by another excellent tee-shot at the par-three 17th and he got up and down from the sand at the par-five third before taking advantage of the short par-four fifth after almost driving the green.
Rozner put a brilliant second to five feet at the third to set up an eagle and made the most of the fifth before getting up and down at the tenth.
A lengthy putt at the 14th then moved him into double figures and he completed the set on the par fives at the 16th despite a ragged tee-shot.
Manassero is playing Scotland's national open for the first time in six years and carded his lowest round at the event with eight birdies and a single bogey.
Im was the man setting the early pace as he turned in 32 from the tenth with three birdies but he could only come home in level par.
McIlroy made five birdies and a bogey in a 66, while Del Rey started his round with six birdies en route to a 62 that matched the lowest effort of the week.
Højgaard carded a 63, Theegala signed for a 65 and Morikawa and Noren both recorded rounds of 66.
