LEMONT, Ill. ? Winning the British Open didn’t protect Ben Curtis from golf’s ups and downs.

He’s been down for most of the last two years, struggling to make cuts let alone a run like the one that won him the Claret Jug in 2003.

On Thursday, though, he was up. Way up. He shot a bogey-free, 7-under 64 in the first round of the Western Open, finishing one stroke shy of the course record and grabbing a share of the lead with Jim Furyk and Todd Fischer.

“I’m still a long ways away from playing really good golf,” Curtis said. “It’s coming, but I’d like to put four good rounds together instead of one or two. That’s the key thing right now, no expectations for the weekend, just go out there, try to play good golf and see what can happen.

“I know I can win, I think I can win,” he added. “But there are still parts of my game that I need to improve on and get more consistent.”

If not, there are plenty of people right behind him. Former Western Open champ Robert Allenby, Chad Campbell, Harrison Frazar and Chris Couch are two strokes back (66), and John Daly is lurking in a big pack at 2-under 69.

Tiger Woods and Vijay Singh both struggled and have work to do to make the cut. Woods couldn’t get the ball close to the pin all afternoon and finished at 2-over 73. Singh shot a 1-over 72.

“If I shoot 64, 65, I’ll be right back in this thing where I could win it,” said Woods, who’s won three times here.

John Daly, left, chats with Ben Curtis while they wait to tee off on the 18th hole during the first round of the Western Open. Curtis shot a 64 Thursday at Cog Hill Golf and Country Club in Lemont, Ill., to share the first-round Western Open lead.

Curtis was a rookie just trying to hold onto his PGA Tour card when he won the British at Royal St. George’s two years ago, beating Singh and Thomas Bjorn by a stroke.

But winning a major didn’t magically transform his game. Far from it. He had one top-10 finish last year, and finished 141st. This year, he’s made the cut twice in 14 tries, and his best finish was a tie for 56th at Wachovia.

“I am in a slump,” he said. “This year has just been up and down. It just seems like one week I’d hit the ball poorly and then the next week I’d putt poorly. So it’s been everything, to be honest.”

After missing the cut at the past three tournaments, Curtis spent last week at home. Instead of getting away from the game, he threw himself into it. And somewhere along the way, things started to click. The better he played, the more confidence he gained. The more confidence he had, the better he played.

He got off to a good start Thursday, making birdie on the first hole, and then picked up five strokes in a six-hole span on the back. He birdied the par-3 12th and par-4 14th, then eagled No. 15.

He used a 3-wood to get within 12 feet from 240 yards out, then made the putt. He followed with another birdie on 17, making a 20-footer that went into the hole as if it was on a track.

“It’s a long year, and I just try to stay positive and try to work through the problems and keep my head up high,” Curtis said. “All you need is a couple good weeks, decent weeks to get your game going and your confidence up, and you never know what can happen.”

Furyk isn’t lacking for confidence. With three runner-up finishes and four more in the top 10, he knows he’s playing well. On Thursday, he was bogey-free, and made four straight birdies on Nos. 5-8.

What he’s missing are victories. The winner of the 2003 U.S. Open at nearby Olympia Fields hasn’t won since the Buick Open that same year, a stretch of 39 events. Granted, he missed much of last season after having wrist surgery.

He’s come close recently, including last weekend’s Barclays Classic. Furyk had a three-stroke lead over Padraig Harrington with five holes to go. But he made back-to-back bogeys on 16 and 17, and Harrington then holed a big-breaking 65-foot putt on 18 for an eagle and a one-stroke win.