HUMBLE, Texas (AP) -- Louis Oosthuizen shot his second straight 6-under 66 on Saturday to reach 17 under and take a two-shot lead over Hunter Mahan after the third round of the Houston Open.
The 29-year-old South African shook off two early bogeys with four straight birdies on a sunny, windy afternoon at Redstone. Mahan had a 65, rebounding from a bogey on No. 9 with four birdies on the back nine.
Carl Pettersson (67) and Brian Davis (69) were three strokes back at 14 under. James Driscoll (71) was alone at 12 under.
Three-time major champion Ernie Els, who must win to qualify for the Masters next week, was in a group at 8 under. Els hasn't missed the Masters since 1993 and knew that his chances of winning Sunday are remote.