Jonas Blixt took control of the Charles Schwab Challenge after claiming a one-stroke lead at the halfway stage on Friday.
Swedish golfer Blitx carded a six-under-par 64 to sit atop the leaderboard after round two at Colonial Country Club in Fort Worth, Texas.
Blixt – who is chasing his fourth PGA Tour win and first since claiming the 2017 Zurich Classic of New Orleans – enjoyed a bogey-free round with four birdies and a hole-out for eagle on the par-four 17th.
The impressive hole-out put Blixt one stroke ahead of Kevin Na and Tony Finau, who are tied for second position, at nine under.
Finau had the 18-hole lead but still remains in contention despite a bogey staining his scorecard early in the round. He played steady golf the rest of the way to finish two-under 68.
Na, who has had success at the Colonial Golf Course in Fort Worth, Texas, shot a 62 for the best round of the day.
Rory Sabbatini has sole possession of fourth place at six under, a stroke ahead of former world number one Jordan Spieth.
Spieth – who was tied for third at the US PGA Championship – posted a 70 to be level alongside Nick Watney (68), Jim Furyk (66), C.T. Pan (67) and Jason Dufner (68).
The three-time major champion had another good day putting. Spieth had a career first when he made three putts from outside 40 feet in a single tournament.
Defending champion Justin Rose was able to make the cut after his three-under-par 67 left him one over after 36 holes.
While Rose qualified for the weekend, the likes of Rickie Fowler, Jon Rahm, Bryson DeChambeau, Xander Schauffele and Zach Johnson missed the cut.