Day two:
Matt Kuchar fired a second-round 69 to lead by one shot after an abbreviated day two of the USPGA Championship at Whistling Straits.
Fog again delayed the start but Kuchar was eight under at the close, one ahead of fellow American Nick Watney.
Northern Ireland's Rory McIlroy and England's Simon Khan are in a seven-way tie for third on five under par.
Bad light meant Tiger Woods played only six holes and was seven off the pace, with half the field still to finish.
Woods, needing a top-15 finish to have a chance of qualifying automatically for the United States Ryder Cup team, was at his erratic yet occasionally brilliant best in parring all six holes before being forced off the course when one under.
At least the world number one, for now, will live to fight another day with a number of high-profile players unlikely to make round three after struggling in testing conditions.
606: DEBATE
What do you make of a fascinating second day in Wisconsin?
With the projected cut at two over, England's Ian Poulter and Paul Casey (both one over with 13 and 11 holes to play respectively) still have plenty to do, while Northern Ireland's US Open champion Graeme McDowell (+3), England's Luke Donald (+3 after nine) and Justin Rose (+4) and Spain's Sergio Garcia (+5 after six) are unlikely to return.
European Ryder Cup captain Colin Montgomerie had very little to cheer about after an 83 which left him bottom of the pile on 18 over. The Scot said: "It's been a very long day, a very long week unfortunately."
The Wisconsin fog once again descended on a very windy Whistling Straits to delay the start of day two by two and half hours but there were breaks in the changeable conditions and Kuchar took full advantage.
The 32-year-old from Florida was one of 78 players still on the course when play was abandoned on Thursday evening and finished his delayed first round to register a 67 before storming back out to card a 69.
He rolled in three straight birdies on his back nine to head into the clubhouse sitting pretty on top of the leaderboard before the overnight leaders had to come out and contend with the increasingly damp and blustery weather.
I'm only three behind and I feel as if I'm playing good golf
Rory McIlroy
"I'm very pleased with the way I've been playing. It's been a great year," said Kuchar, whose victory at Turning Stone last year was only his second on the PGA Tour and first since 2002.
"There's definitely an element of luck involved in winning. The best way to approach a week is to give yourself a chance Sunday, and if fate is on your side, you find yourself in the winner's circle."
Overnight leader Bubba Watson began his round in glorious style but fluffed a four-foot putt to miss out on a third consecutive birdie before three bogeys pegged him back to three under with nine holes still to play.
After his opening 69, Khan was tied for the lead with Kuchar on eight under at one stage thanks to three birdies on the back nine.
However, the Chingford star, winner of Europe's PGA Championship at Wentworth in May, crumpled in the closing stages with bogeys on the last three holes to leave him in the chasing pack three shots adrift.
"I didn't feel I did a lot wrong," Khan said. "I generally played well and it was just a shame about the finish but I'm still right in there."
Scotland's Martin Laird is also well-placed on four under with 10 holes still to play, but 21-year-old McIlroy could be the one most likely to threaten top-spot after an impressive 68.
Five birdies and one bogey got the Holywood native within three shots of the leader, with the highlight of his round a stunning chip to within 20 feet from a tricky position before sinking the putt for birdie at the eighth.
"The key is to just keep the mistakes off the card and I was lucky I did that," McIlroy said. "I think my chances are good, I'm only three behind and I feel as if I'm playing good golf."
South Africa's Ernie Els finished on two under, after a double-bogey on the last, alongside US Masters champion and world number two Phil Mickelson, who carded a three-under 69.
Mickelson, who began treatment for arthritis two weeks ago, said: "I did well and I'm within striking distance. I feel much better.
"I feel terrific now. I'd like to be higher up but I feel I can go and shoot six under and be right back in it."
Ireland's Padraig Harrington, eyeing one of Montgomerie's three wild cards for the Ryder Cup at Celtic Manor in October, bounced back from his first-round 75 to knock in four birdies in six holes at the start of his second round.
BBC Sport
I guess I should admit that I'm also pulling for my home state guy, Steve Stricker. If he could pull it off, the place would go wild as if the Packers won the Super Bowl. And even with Phil's disclosure of his illness, there is something special about the guy. The main thing on this course though is, you must drive the ball straight and keep it on the fairway. f you don't do that trust me, you're dead.
