Justin Thomas found some much-needed form ahead of the Ryder Cup as he shot a second round 67 in the Fortinet Championship.
Sahith Theegala shot a 64 to tie SH Kim at 12-under-par on top of the leaderboard.
But it is the presence of Thomas, winless on the PGA Tour this season and reliant on a wildcard pick from Ryder Cup captain Zach Johnson, four strokes back in a tie for sixth which caught the eye.
Having hit just three fairways in an opening 69, Thomas switched to a longer driver he has been experimenting with in recent weeks.
“I could tell in one video I was getting stuck underneath it,” said the double major winner, who hit eight fairways in the second round. “If I drive it like I did today, I’ll use it for the rest of my career.
“I had a good thought from just a little 10-minute range session that I felt like could get me through today and it worked pretty well.
“That’s a part of what I think has made me as successful as I’ve been in my career, I’ve been very good at adjusting on the fly.”
Thomas’ fellow Ryder Cup player Max Homa was among those tied with him on eight-under-par, one better than a group including English duo Callum Tarren and Harry Hall.
US Ryder Cup captain Johnson was among those to miss the cut.