Will Claxton shot a 3-under 69 on Friday on PGA West's TPC Stadium Course to increase his lead to two strokes after the third round of the PGA Tour Qualifying Tournament.
Claxton, a former Auburn University player, had a 13-under 203 total.
The top 25 in the six-round event will earn 2012 PGA Tour cards.
Bobby Gates and Matt Jones were tied for second. Gates shot a 68, and Jones had a 70. They also played the Stadium Course.
Rising Korean star Seung-yul Noh had the round of the day, a bogey-free 8-under 64, to jump from 30th to a tie for second place.
Vaughn Taylor, a former Ryder Cup player, stands level with Billy Hurley III in fifth after a 69, giving himself a decent chance of earning a card for next season.
Few of the big names are well placed at the halfway stage.
2002 PGA Championship winner Rich Beem moved into contention after following two opening level-par rounds with a 5-under 67 to climb into a share of 33rd place. But three former major champions have plenty of catching up to do.
David Duval, the former British Open champion and world No. 1, matched Beem in the first two rounds but a 73 saw him nudged back into a share of 115th on 1 over.
Shaun Micheel, the 2003 PGA Champion, started brightly with a 5-under 67 in his first round but followed that with a 75 and a third round of 74 saw him drift back into a tie for 107th on level par.
Two-time U.S. Open winner Lee Janzen had his best round of the week, adding a 4-under 68 to previous rounds of 71 and 75. The 47-year-old shares 73rd place, with former Ryder Cup player Boo Weekley on the same 2-under-par aggregate.
Jeff Maggert, who played on three Ryder Cup teams in the 1990s, fell back from a tie for ninth to a tie for 27th after a 72.