Sung Kang produced a dominant performance to claim a four-stroke lead after the second round of the Bryon Nelson.

South Korean Kang carded a 10-under-par 61 as he surged to the top of the leaderboard on Friday.

Kang – who is looking for his first PGA Tour win – converted six consecutive birdies from the fifth hole, helping him to 16 under heading into the weekend at Trinity Forest Golf Club.

Americans Matt Every (65) and Tyler Duncan (66) moved into a tie for second, while three-time major champion Brooks Koepka is a stroke further ack at 11 under.

Reigning U.S. Open champion Koepka dropped from third after the first round to fourth, despite a five-under-par 66.

Former world number one Jordan Spieth, meanwhile, posted a 67 to be nine shots off the pace.

Denny McCarthy – the solo leader after round one – had a six-over showing that dropped him far down the leaderboard into a tie for 67th.