(CNN) -- The United States will take a three-point lead over the International team into the final day's 12 singles matches after extending their Presidents Cup advantage on day three in San Francisco.
Phil Mickelson (left) and Sean O'Hair were unbeaten in both their match as the United States closed on victory.
Fred Couples' American team led Greg Norman's Internationals by 12.5 to 9.5 at Harding Park after a day of five foursomes and five fourballs matches which saw the world's top three players, Tiger Woods, Phil Mickelson and Steve Stricker, lead from the front in both sessions.
After an opening two days of nip-and-tuck contests, the U.S. finally put daylight between themselves and the Internationals as Woods and Stricker came from behind to defeat Tim Clark and Mike Weir to give their team a 10-7 lead at the end of the morning's foursomes.
Woods and Stricker were one down after 16 but won one up as world No.1 Woods sent down a tricky birdie putt at the 17th to square the match and then at the 18th fired a laser-like approach shot to the green in the alternate-shot format.
"It was fun to watch," Stricker told reporters. "I had a front row seat today. That was pretty cool. We all know what he does and he stepped it up when he had to here. It was pretty impressive."
Mickelson had retained his 100 per cent record at Harding Park, chalking up a third consecutive victory with a third different partner as he and Sean O'Hair dominated against Retief Goosen and Camilo Villegas in a five and three win.
Norman then benched the International pair for the afternoon's fourballs. In that better ball format, the Internationals looked well placed to make a comeback as Ernie Els and Mike Weir led from the first hole against Zach Johnson and Justin Leonard to win five and three,
Then Australian duo Geoff Ogilvy and Robert Allenby scored a two-and-one win over Stewart Cink and Lucas Glover to take the overall score to within a point at 10-9 to the Americans.
The first American point of the late session was delivered by Jim Furyk as he and Anthony Kim defeated Angel Cabrera of Argentina and Australia's Adam Scott two and one.
Scott birdied the 16th to leave the Americans just one up and when Cabrera birdied the 17th it looked like the match would be decided at the 18th, only for Furyk to pull out a pressure birdie putt to halve the hole and then birdie the last to seal the victory.
Woods and Stricker continued their unbeaten run this week with a fourth consecutive victory, this time over Ryo Ishikawa and Woods' U.S. PGA Championship nemesis YE Yang.
The Americans were romping to victory at six up after 12 holes, world number three Stricker leading the way with seven birdies in their better ball round.
Yang won a hole for the Internationals at the 13th, leaving the Americans dormie five, although there was still fight from the Asian duo with Ishikawa winning the next hole.
The Japanese teenager, one of Norman's captain's picks alongside Scott, was not down yet and he birdied the 15th to leave the Americans three up with three to play.
That was when Woods stepped up a gear and finished the contest, his birdie three at the 16th sealing a four and two win.
That gave the Americans a 12-9 lead but Norman had Vijay Singh and Tim Clark leading Phil Mickelson and Sean O'Hair, two up through 11 holes.
Mickelson was kept together with O'Hair from their morning foursomes and the world number two birdied back for the Americans at the 12th to cut the International lead to one hole.
Then O'Hair birdied the 13th to make the match all square with five to play and neither team managed to break the deadlock, Mickelson keeping his unbeaten record intact as he and O'Hair halved the match.