Veteran Jay Haas edged closer to his first PGA Tour win for more than 10 years yesterday with a four-under-par 66 for the halfway lead at the Tour Championship in Atlanata.

The 50-year-old, the oldest player in the field at the East Lake Golf Club, moved to seven under par for the tournament with three birdies and a chip-in eagle on the par-five ninth.

Canadian Stephen Ames is alone in second place at five under after a four-under-par 66 while Tiger Woods lurked a further shot back after a superb six-under-par 64 - his best round since February at the Nissan Open.

Level with Woods is South African Retief Goosen who shot a 66. Canadian Mike Weir and first round co-leader Jerry Kelly are tied for fifth at two under, four shots off the lead.

World number one Vijay Singh, attempting to win 10 events in a single season, struggled to a three-over-par 73 which included six bogeys and he finds himself eight shots back of Haas.

While Woods was on the move Darren Clarke and Padraig Harrington both found the back nine a major struggle.

Clarke, after reaching the turn in level par 35, dropped three shots on the homeward run for three over par 73 and a tie for 10th place on level par 140.

Harrington's day started with a birdie and finished with another at the 18th but in between there was a lot of indifferent golf.

Out in one over 36, Harrington also found trouble on the the back nine. Two birdies, two pars, four bogeys and a double bogey tells its own story as he slipped from a share of sixth place to 23rd on 144.

Woods, meanwhile, believes he is finally coming out of the slump that cost him his world number one spot this year.

After a bogey-free second round six-under-par 64 yesterday, Woods said the self-enforced changes he has made to his swing were paying off.

"I feel the things I've been working on are starting to solidify," Woods said. "I feel like the checklist is becoming shorter and shorter. I don't have to work on as many things when I go out to the range. I don't have to stand out there beating balls for hour upon hour trying to find something. They're just quick fixes and I can go about my business."

Woods, who has been overtaken in the world rankings by Fiji's Vijay Singh and South African Ernie Els, last won a strokeplay event 13 months ago when his domination of the game was still absolute.

There have been occasions this year when he threatened to spark, but each time he slipped back down the leaderboard as he struggled to find the inspiration that has bagged him eight majors and kept him number one for more than five years.

Woods has played better of late with three top 10 finishes in his last three events, including runner-up spots at the WGC-NEC and the Deutsche Bank Championship.

His 64 yesterday equalled his best round of the year, matching his feat at the Nissan Open at the end of February.

"If I play my best, I'm pretty tough to beat," Woods said. "I would like to play my best more frequently, and that's the whole idea. "That's why you make changes."