RENO, Nevada (AP) - Australian Nick O'Hern took advantage of calm morning conditions as one of the first players off the tee Thursday to shoot a 7-under-par 65 and take a one-stroke lead over Chris Riley in the first round of the Reno-Tahoe Open.

"Can't play much better than that," said O'Hern, who made six of his seven birdies on putts from 10 feet or closer while posting the only bogey-free round of the day at the 7,472-yard Montreux Golf & Country Club.

"Missed a couple of putts but every time I hit an ornery shot I got it up and down for par, so I kept the round going," he said.

Riley, a former star from the nearby University of Nevada, Las Vegas, had one bogey in his round of 6-under 66. He earned a spot on the President's Cup team after his first tour victory at Reno in 2002, and is one of the seven past champions playing in the 13th year of the event on the mountain course designed by Jack Nicklaus.

Will MacKenzie, the 2006 champ, was another stroke back at 67 tied for third with Blake Adams and Briny Baird. Baird, who holed out from 100 yards for an eagle on the 584-yard, par-5 No. 2, was one of only two players among the top 20 on Thursday who teed off in the afternoon's swirling winds.

"The strength of the wind wasn't as bad as the direction of the wind," Baird said. "It would be complete different directions from hole to hole, so that made it tough."

Steve Flesch, who won in 2007, shot a 68 along with Shaun Micheel, Rod Pampling, Jay Williamson, Matt Jones, Ben Martin and Robert Garrigus. Garrigus also played in the afternoon

Vaughn Taylor - the tournament's only two-time winner in 2004 and 2005 - shot a 69. Kirk Triplett (2003) had a 70, Notah Begay III (1999) 71 and Parker McLachlin (2008) 74.

Defending champ Matt Bettencourt birdied two of his first four holes and was 2-under par through 6 before a rib injury forced him to withdraw.

Among other notable players, Justin Leonard and Scott McCarron shot 71; Rocco Mediate and Jose Maria Olazabal 72; John Daly 74 and David Duvall 78.

O'Hern, Riley and the vast majority of the players who fared best Thursday were in early morning groups that had a clear advantage over those in the afternoon when scores averaged more than 1.5 strokes higher.

The wind, combined with a number of elevation changes, makes it especially difficult to calculate distances where the ball travels up to 10 percent farther than at sea level at the tree-lined layout roughly 5,500 feet above sea level, in the shadow of 10,776-foot tall Mount Rose.

"I do enjoy the fact that the ball goes a long way because I'm a short hitter. So it's nice to get the driving stats up," O'Hern said about the course where 40 percent of the drives were 300 yards or longer last year - tops on the PGA Tour.

"I played well last week at the Greenbrier but had a cold putter. It was nice to finally get the putter warmed up," he said.

With the exceptions of Flesch and Triplett, all of the past winners in the field this week claimed their first tour victory at Reno and O'Hern would like to do the same.

The 39-year-old, who joined the PGA tour in 2005, came close with a tie for second at the Booz Allen Classic in 2006. His best year was 2007 when he earned $1.3 million, was named to the President's Cup team and became the only player to twice knock Tiger Woods out of the World Golf Championships-Accenture Match Play Championship. He also did it in 2005.

This year, he's 121st on the money list with $513,489, his best showing a tie for sixth at the Heritage in April.

O'Hern said Thursday he wasn't bothered by the tricky mountain greens with optical illusions that make it hard to tell which way the ball will break.

"I just went with my gut," he said.