HALFWAY CLUBHOUSE LEADERS US unless stated -9 C Campbell, A Scott (Aus) -8 D Clarke (NI), B Davis (Eng) -7 C Montgomerie (Sco), JL Lewis

Adam Scott and Chad Campbell led the way on nine under after round two, and could face a play-off to decide the winner if the bad weather continues.

Darren Clarke and Brian Davis are one shot back, and Colin Montgomerie's 64 took him to seven under.

Tiger Woods is four shots adrift as he tries to return to world number one.

Organisers were forced to play catch-up after a four-hour delay on Friday and no play on Saturday.

They managed to complete round two, but just 12 players made it out for their third round before the rain intervened again, with more bad weather forecast for Monday.

"We're going to make every effort to play," said PGA Tour tournament director Mark Russell.

"We're going to come back, try to finish the third round and see how it goes from there."

American Campbell shot a second-round 65 on Friday, while his Australian rival Scott joined him on top of the leaderboard 24 hours later after a 66.

Davis, who led after an opening 65 on Thursday, had not hit a shot since 1400 local time that day.

The Englishman dropped a shot over the first nine holes, but responded with three birdies to close to within a shot of the leaders.

To play the last 10 holes in five-under is good for me Colin Montgomerie

Clarke parred the last three holes of his front nine, then played a superb bunker shot to five feet on the 10th and holed from 13 feet at the par five next.

Another birdie at the 16th gave him a three-under 68.

Montgomerie was joint 33rd on two under when he began, but was tied for third by the time he reached the 14th tee.

He chipped in from nearly 20 yards for an eagle at the 10th, then birdied the 12th and 13th from 11 and seven feet.

Three more birdies at the 18th, first and sixth followed to give him his best round on American soil.

Montgomerie was joined on seven under by American JL Lewis, who shot 65.

Woods, who needs a top-four finish to reclaim the number one ranking from Vijay Singh, double-bogeyed the 18th in a round of 70 to finish on five under and a tie for 13th place.