Will Claxton shot a two-under 70 on Saturday stroke lead after four rounds of PGA Tour Q School.

Claxton started the tournament with a 64 and has held at least a piece of the lead since. He ended 72 holes at 15-under-par 273.

Marco Dawson, in his 11th appearance at Q School, fired a five-under 67 to climb into second place at 13-under 275. He has earned his card five times via this event, the last time in 2006.

Seung-yul Noh (72) and Harris English (70) are tied for third at minus-11. Noh was challenging for the lead, but bogeyed 17 and quadruple-bogeyed 18 to drop five strokes. English won this year on the Nationwide Tour as an amateur, but has never appeared in a PGA Tour event.

Bobby Gates, who finished 126th on the PGA Tour money list in 2011, ended 72 holes at 10-under 278 after tripping to a 73 on Saturday.

Brett Wetterich, who won the Byron Nelson Championship in 2006, and 2002 PGA Champion Rich Beem both were in position to regain their tour cards entering the fourth round.

Wetterich faltered to a 13-over 85 and tumbled from a tie for ninth into a share of 125th. Beem struggled to an eight-over 80 and slid from a share of 33rd into a tie for 102nd. Wetterich is plus-five, while Beem is plus-three.

With two rounds to go, five-under par is the number players need to be at to be inside the top 25, which will give them their PGA Tour card for 2012.

The next number of finishers nearest 50 after the Qualifying Tournament will earn fully exempt Nationwide Tour cards for 2012 and the remainder of the field will receive conditional Nationwide Tour status.

The field has now played two rounds apiece on the Nicklaus Tournament Course and TPC Stadium Course at PGA West. Everyone will play both courses one more time. The leaders will play the Stadium Course in round five and the Nicklaus Tournament Course in round six on Monday.

Claxton had a steady round. He opened with a birdie on the second and moved to 15-under with a birdie on the par-five seventh on the Nicklaus Tournament Course.

Claxton tripped to a bogey on the ninth, but atoned for that error with a birdie on the par-three 12th. Claxton parred out to end at minus-15.

Dawson had a bogey-free round with three birdies in a four-hole span from the fourth. Around the turn, he also birdied 11 and 14 to move within two of Claxton.

NOTES: Claxton has one previous PGA Tour start at the 2011 Transitions Championship, where he tied for 67th...Dawson and Ryan Yip shared low round of the day honors with their 67s...Andre Stolz and Matt McQuillan withdrew after the third round, while Nate Smith and Cliff Kresge withdrew during the fourth round.