Golf:Patrick Cantlay made the most of his high-profile grouping at the Frys.com Open last night, the amateur outscoring his playing partners Tiger Woods and Louis Oosthuizen in the opening round.

The 19-year-old University of California student fired a two-under-par 69 in tricky scoring conditions at CordeValle Golf Club to beat Woods by four shots and Oosthuizen by two.

"It was fun," Cantlay said after mixing three birdies with a lone bogey at the par-four 13th. "I had a good time out there and really enjoyed myself."

Asked if he was surprised that former world number one Woods had struggled to an opening 73 in his first PGA Tour appearance in nearly two months, Cantlay replied matter-of-factly: "He played how he played.

"I didn't have any expectations for what he was going to do or what anybody else was going to do except for myself."

He shrugged off any suggestion that outscoring the 14-times major winner had been in any way significant. "No," he added. "It's the first round of a tournament, so it doesn't mean anything."

Brendan Steele, Briny Baird, Garrett Willis and Matt Bettencourt all share the lead after the first round. While Woods struggled in wet and cold conditions, Steele and company fired four-under-par 67s to set the first-round pace.

World number 20 Paul Casey, the highest-ranked player in the field, briefly held a share of the lead before dropping four shots in the last six holes to card a 70.

Woods, who has not competed since he missed the cut at the PGA Championship in August, struggled badly with his putting on the way to an erratic 73.

"That's probably one of the worst putting rounds I've ever had," he said after totalling 27 putts and reaching just nine greens in regulation. "Whatever momentum I could have gotten by hitting good shots, I just missed putts.

"I am just playing to be competitive and to win a golf tournament," added Woods, who is taking part in a Fall Series event for the first time at the urging of Presidents Cup captain Fred Couples.