Russell Henley made four birdies on each of the front and back nines for a two-round score of 16-under-par 126 and a three-shot lead.
The American started on the back nine and started with three consecutive birdies on the 11th hole and another on the 17th to turn in a 31. After the turn he holed a 25-foot putt for birdie on the third and then made three more birdies in a row from the sixth. On six, he attacked the green with a shot that swung backwards from behind the flagstick to the front, leaving 12 feet to go, and he holed out in one. On the seventh, he made a putt off the green to take a six-foot putt. On the eighth, he nearly holed a hole-in-one, sinking a short 3-foot putt.
"It's felt good the last two days. Mentally very confident and trusting in what I'm doing," said Russell-Henry, "I got on a lot of fairways and had some nice par saves and that kept me going this round. Very obviously I'm happy with where I'm at."
Will Gordon shot a 62 in the first round to take the lead and had a much quieter round, but he made no bogeys and made four birdies for a 67. Sam Ryder made seven birdies on the front nine, but made a couple of mistakes after the turn to shoot 65. Will Gordon is tied for second place with Sam Ryder at 13-under-par 129.
Patton Kizzire shot his second consecutive round of 65 to finish in fourth place. Sweden's David Lingmerth made four birdies in his last six holes to card a 66 and finish in fifth place on 11-under-par 131.
Harry Higgs turned in the day's low round of 62 to move up to a tie for sixth.
Ng Bik Yuen made back-to-back birdies on the last two holes to post a 66 and is in a big group tied for 14th at eight-under-par 134. Double defending champion Viktor Hovland (69) and Colin Morikawa (63) tied him.
World number two Scotty Scheffler had two birdies and two bogeys for a 71 to drop to a tie for 29th place at six-under-par 136.
Dou Zexing went out with a double bogey and did not bounce back, shooting 72 for a two-round 141 (69-72), one under par, and suffering elimination. Yu Junan 75-67 and Pan Zhengjun 72-75 also failed to advance.