A double bogey at the last hole left Ian Poulter in a share of the lead with Zach Johnson at the end of the first round of a Tiger-less Chevron World Challenge in California. With the world number one staying away from his own tournament, which annually benefits the Tiger Woods Foundation, amid speculation about his private life, ticket holders at Sherwood Country Club near Los Angeles were offered refunds in his absence.

Those who chose to attend anyway watched England's Poulter lead the 18-man field for most of his round, only to miss the fairway off the 18th tee on the way to a double bogey which left him with a four-under 68, tied with American former Masters champion Johnson.

Ireland's Padraig Harrington, the winner in 2002, finished in third place following a 69 with Jim Furyk, US PGA champion YE Yang and Open champion Stewart Cink a shot behind having each carded 70s.

"There's plenty of good guys here and plenty of winners here as well so it's nice to have some sort of track record on the course," Harrington said. "I feel good about my chances going forward."

Newly crowned Race to Dubai winner Lee Westwood, the world number four, briefly shared the lead with his compatriot Poulter at five under before falling away on the back nine to one under having posted an opening 71, including a double bogey at the last.

"I played pretty well around the front nine, it's just a shame I didn't finish it off," Westwood said.

"I left a lot of good shots out there and if you get bad shots out there it's going to penalise you.

"So I got what I deserved in the end with a double bogey at the last."

Westwood found a wooded area to the right of the fairway off the 18th tee and on an uphill lie and lost his footing on his downswing.

"I've just pulled something, not much I don't think. My back foot went as I came into the ball and it did hurt but I should be all right."

Westwood will start the second round alongside Americans Anthony Kim, Sean O'Hair and Steve Stricker, the world number three, and also Graeme McDowell, Woods' last-minute replacement in the field.

The Northern Irishman, handed a late chance to jump back into the world's top 50 from his current ranking of 55, made a slow start but sparked into life with a long birdie putt at the par-three 15th.

Germany's Martin Kaymer finished with a one-over 73 while England's Paul Casey, who has played only twice since aggravating a rib injury and withdrawing from the WGC-Bridgestone Invitational at the start of August, posted a three-over-par 75.