Will Claxton shot a 2-under 70 on Saturday on PGA West's Nicklaus Tournament Course to maintain his two-stroke lead after the fourth round of the PGA Tour Qualifying Tournament.
Claxton had a 15-under 273 total.
The top 25 in the six-round event will earn 2012 PGA Tour cards.
Marco Dawson was second after a 67 on the Nicklaus course.
Harris English and South Korean Noh Seung-yul were equal third at 11 under. English shot a 70 and Noh had a 72 -- both on the Nicklaus course.
Windy conditions made low-scoring difficult, as only five players in the 167-man field bettered Claxton's score of 70, and with two rounds remaining the former Auburn University player looks to be heading for a 2012 card, having led all the way so far.
Noh had a 72 to follow Friday's 64, while English matched Claxton's 70.
Australian Matt Jones went backward from a tie for second to a tie for 21st after a 78 that contained two double bogeys.
Ryan Yip was among the players level with Jones on 5 under par for the week, having moved in the other direction, shooting up from 107th with a 67.
Vaughn Taylor, a former U.S. Ryder Cup player, fell a place to sixth with a steady 73.
A total of 25 cards for 2012 are up for grabs, with several former major champions competing.
The 2002 PGA Championship winner Rich Beem had moved into contention after a third round of 67, but an 80 saw him tumble to a tied for 102nd on 3 over for the week.
David Duval, the former British Open champion and world No. 1, has scored consistently across his four rounds but needs to make a move. Rounds of 72, 72, 73 and 73 have left him 2 over.
Shaun Micheel, the 2003 PGA Champion, is sharing 55th place after a 71 put him 1 under.
Two-time U.S. Open winner Lee Janzen followed Friday's 68 with a handy 71, bearing in mind the conditions, to stand tied for 41st on 3 under. Jeff Maggert, who played on three Ryder Cup teams in the 1990s, was also 3 under after a 75, as was England's Greg Owen following a 69.
Former Ryder Cup player Boo Weekley drifted to 4 over after a 78.