Former Open Championship winner Ben Curtis will take a three-shot lead into the final round of the Valero Texas Open as he looks to end a six-year title wait.

The 34-year-old American extended his overnight lead by a single stroke today despite an erratic round of 73 that included a pair of double bogeys.

Curtis had been flawless through the opening two days at TPC San Antonio, but he fell foul of the treacherous conditions from the start as he took six to double bogey the first.

It got worse with a seven at the par-five eighth, to go out in 39, but he bounced back with three birdies and a bogey after the turn which proved enough to extend his lead at nine under.

Curtis saw his closest challenger and playing partner David Mathis implode with a five-over 77, to leave Matt Every as the closest challenger on six under.

Every, who shot a course-record 63 on the opening day, kept in contention with a 73 combining three bogeys with a pair of birdies. The 28-year-old is yet to win on the PGA Tour.

On a day of high scoring John Huh defied the numbers to go around in the day's equal-best round of five-under 67 and be in a tie for third on four under with South Korean duo Charlie Wi and Noh Seung-yul.

Matt Kuchar, who finished in a tie for third at The Masters, joined Huh in shooting 67 to join Mathis in a group of five players on three under, but with six shots to make up tomorrow he has a mountain to climb.