Venue: Harding Park Golf Course, San Francisco Dates: 8-11 October
Coverage: Reports on BBC Radio 5 live and on the BBC Sport website. Live on British Eurosport
Woods rallied superbly in the morning fousomes
The United States need only five points from Sunday's 12 singles after taking a 12½-9½ lead against the International team in the Presidents Cup.
Tiger Woods and Steve Stricker won both their matches on Saturday to complete a sweep of four victories in the week.
Phil Mickelson had a chance to emulate them but halved his second match.
No team has rallied from three points behind on the final day to win the cup outright, and in the seven competitions USA have lost only one singles session.
Woods and Stricker are the first partners to win four and lose none in any team competition since Larry Nelson and Lanny Wadkins won all their matches in the 1979 Ryder Cup at The Greenbrier.
But they looked certain to lose against Mike Weir and Tim Clark in the morning foursomes, one of three matches the Internationals were up in at the time.
One ahead on the 17th green, former Masters champion Weir had a five-foot putt for a birdie, while Woods found the bunker after trying to drive the green and Stricker's escape finished 25 feet away.
But Woods saw his birdie putt tumble in on the final roll, Weir missed his and the match was all square.
From the final fairway Woods sent a three-iron to eight feet and the putt and match was conceded when Clark blasted a bunker shot long.
Stewart Cink and Hunter Mahan cobbled together a birdie on the final hole to earn a halve against Robert Allenby and Vijay Singh after trailing the previous 13 holes to give the Americans a 10-7 advantage after the morning foursomes.
Obviously we have to win eight matches out of 12, which a lot of people are probably going to say is a tall task, but it can be done and it has been done
Stricker was in superb form with the putter in the afternoon fourballs as the dominant Americans inflicted a first defeat of the week for USPGA champion YE Yang and 18-year-old Ryo Ishikawa.
He had seven consecutive threes and revealed afterwards he was inspired by his illustrious playing partner.
"What he did in the morning round made me want to do something and step up a little bit," Stricker said. "Fortunately, I was rolling it pretty well."
Mickelson and Sean O'Hair were two down with seven holes to play in their fourballs match against Clark and Vijay Singh.
Mickelson birdied the 12th and O'Hair picked up a birdie at the next but Clark restored the lead for the Internationals by hitting it so close at the 14th that the putt had to be conceded.
The match was all square again when three-time major winner Mickelson holed from 40 feet, but on the final green after the three other players missed birdie putts, the left-hander's effort stayed just to the right of the hole.
The half still left the US with a commanding advantage, particularly given their strong singles record, and the fact that they have never lost a Presidents Cup on American soil.
Former US Open champion Geoff Ogilvy, who collected his first point of the week when he partnered compatriot Allenby to victory in the fourballs, admitted: "Last time we had a five-point mountain to climb in Montreal, and it looks like we will have something to climb."
But team captain Greg Norman remained in confident mood and said: "We feel like we are still close enough.
"Obviously we have to win eight matches out of 12, which a lot of people are probably going to say is a tall task, but it can be done and it has been done."
That remarkable finale resulted in a victory for the American team, however, at the inaugural Presidents Cup in 1994, when they won the last day singles 8-4 to clinch the trophy 20-12.
The US are seeking their third successive title and were last denied victory when the teams drew 17-17 in South Africa in 2003.
The sole Presidents Cup victory by the Internationals came in 1998 when the event was staged in Melbourne.
Saturday's foursomes results (US first):
Mickelson/Sean O'Hair beat Goosen/Villegas 5&3
Leonard/Furyk beat Els/Scott 4&2
Cink/Mahan halved with Allenby/Singh
Perry/Johnson lost to Yang/Ishikawa 3&2
Woods/Stricker beat Weir/Clark 1 up
Saturday's fourballs results (US first):
Kim/Furyk beat Cabrera/Scott 2 up
Cink/Glover lost to Ogilvy/Allenby 2&1
Johnson/Leonard lost to Els/Weir 5&3
Woods/Strickerbeat Ishikawa/Yang 4&2
Mickelson/O'Hairhalved with Singh/Clark