Days after recording his first PGA Tour win, Sam Burns is shooting for another, carding a career-low 10-under-par 62 to take the lead at the AT&T Byron Nelson as Jordan Spieth slid and Brooks Koepka missed the cut.
Burns turned in a second consecutive bogey-free round at TPC Craig Ranch in Dallas, entering the weekend with a two-stroke lead on Alex Noren at 17 under for the tournament.
Friday's second round marked the fifth time this season Burns has held at least a share of the lead after two rounds, the most of any player on Tour.
The 24-year-old American finally capitalised on that success at the Valspar Championship a fortnight ago, winning by three strokes over Keegan Bradley.
If he holds on in Dallas, Burns would be the first player since Camilo Villegas to earn his first two tour wins in consecutive starts.
Sweden's Noren is outright second following his eight-under-par 64, a shot better off than South Korean golfer Lee Kyoung-hoon (65) at 15 under.
Former world number one Spieth, who ended the opening round tied for the lead alongside J.J. Spaun, dropped five places.
Local favourite Spieth slumped to a two-under-par 70 to be tied for sixth position with five others, six strokes adrift of Burns at the halfway stage.
World number three Jon Rahm (69) and U.S. Open champion Bryson DeChambeau (68) are 10 shots back at seven under for the event.
Masters champion Hideki Matsuyama – back in action for the first time since his triumph – closed out the second day six under through 36 holes following a two-under-par 70.
Matsuyama made history as he became the first Japanese man to win a major tournament after claiming The Masters by one shot in a thrilling finale at Augusta in April.
He finished ahead of runner-up Will Zalatoris (68), who is also six under heading into Saturday's third round.
Four-time major champion Koepka (70) – AT&T Byron Nelson runner-up in 2016 – missed the cut after finishing three under, below the six-under line.
Sergio Garcia (75), who won the tournament five years ago, Rickie Fowler (72) and former world number one Jason Day (69) also failed to qualify for the weekend.