Major winners Mickelson, Ogilvy and Woods were difficult to separate

Woods, 30, had not fired on all cylinders but ground out a 68 to catch one playing partner, Geoff Ogilvy, and keep the other, Phil Mickelson, at bay.

Ogilvy also shot 68 for seven under as Mickelson limped to 71 and four under.

"I didn't do anything special. I just hung around and didn't make any mistakes," said Woods.

"You've got to go out there and understand there's going to be a bunch of guys probably within four or five shots of the lead, and go out there and make some birdies here and there and try not to give anything back."

South African Ernie Els carded a two-under 70 for three under overall, while countryman Retief Goosen was one under and America's world number three Jim Furyk ended two under.

Experience-wise, a lot of guys would kill for experience like that Geoff Ogilvy

But Fiji's Vijay Singh, a two-time USPGA winner, missed the cut by one after carding 73, 72 for one over.

Other big names to miss the cut include US Ryder Cup captain Tom Lehman, K Club wildcard candidate Fred Couples and crowd favourite John Daly.

Potential European Ryder Cup players to get the weekend off include Ireland's Padraig Harrington, Dane Thomas Bjorn and US-based Swede Carl Pettersson.

Woods, Mickelson and Ogilvy were pitted together according to tradition as the year's three major champions and were locked at three under par going into round two.

But after cagey starts it was Australian Ogilvy, the US Open champion, who was in danger of upstaging his more illustrious rivals.

The 29-year-old fired four straight birdies from the 4th to climb to seven under. He wobbled just after the turn and leaked back-to-back bogeys on 11 and 12 but made amends with two more birdies at the 13 and 15th.

I'm only four back but I feel like I'm playing army golf - left, right, left Phil Mickelson

"All in all it was good fun and I'm happy with how I played," said Ogilvy. "It can only help in the future, whether you play well or badly in a group like that. Experience-wise, a lot of guys would kill for experience like that."

Open champion Woods, meanwhile, made his move with an adventurous birdie on the long 5th and added another at the par-five 7th to reach the turn five under.

The 11-time major winner, who won the first of his two USPGA titles at Medinah in 1999, escaped with a circuitous par on the 10th and found birdies hard to come by until the 14th and the symbolic 10-footer on 18.

Mickelson, the world number two, struggled with his driving - he hit nine of 14 fairways - and had to rely on his scrambling skills to stay in contention.

But the defending champion, who shares a frosty relationship with Woods, will have been pleased to dampen his countryman's celebrations on the last with a long birdie putt of his own after finding yet more rough off the tee.

"I'm only four back but I feel like I'm playing army golf - left, right, left," said Mickelson.

"My ball striking has not been very good, but I feel it's just one little thing. My short game has kept me in there but I'm fighting, man, I'm fighting."

The 36-year-old's short-game coach Dave Pelz added extra spice earlier in the week by saying Mickelson is better than Woods on his day.