Tiger Woods sank a tense 15-foot birdie putt to put the US all-square with the Internationals 11-11 in the Presidents Cup with just one day's play to go.
The world number one and Jim Furyk beat Fiji's Vijay Singh and Australian Stuart Appleby 2-up to tie the Cup for the first time going into the Sunday.
Fred Couples missed an eight-foot birdie putt on the 18th that would have given the US the lead in Virginia.
It meant he and Davis Love halved with Angel Cabrera and Michael Campbell.
Also in the afternoon's fourballs, South Africa's Retief Goosen and Australian Adam Scott routed American pairing Justin Leonard and Scott Verplank 5 and 4 in a duel of unbeaten duos.
Twice US Open champion Goosen said: "We played very well, we just seem to play a similar sort of game. We gel well with each other."
Australian Mark Hensby and South African Tim Clark also notched up a win for the Internationals, defeating Kenny Perry and Stewart Cink 5 and 3.
"We've got a great chance"
But Phil Mickleson and Chris DiMarco pounded Aussie duo Peter Lonard and Nick O'Hern 6 and 5.
"Chris played really well and I have enjoyed playing with him," said Mickelson. "We have been able to feed off each other and it has been a good, fun couple of days."
Trailing by 6½-5½ overnight, the US pulled level on 8½ points after winning the morning foursomes 3-2.
Woods, who showed little sign of the back pain that had bothered him on Friday, and Furyk then recovered from one down with six to play to win their crucial afternoon contest to keep the pressure on.
"We had a tough match. It's nice to get a point," said Furyk, who made the duo's only six birdies over 14 holes.
But Singh criticised Woods and Furyk for slow play after they took time helping each other read putts.
Singh fumed: "The way we lost, it wasn't right. Just too slow.
"It's OK when they're hitting the ball, but around the greens it took forever. Toward the end it took its toll."
Meanwhile, it will be the first time the Americans have not held the upper hand going into the last-day singles matches.
And the Internationals are feeling confident they can inflict America's first Cup defeat on home soil.
"We've got a great chance," said Scott after the penultimate day.
Both teams need 6½ points to take the trophy outright but in the event of a draw there will not be a play-off and the Cup will be shared.
The Cup was also shared in 2003 in South Africa but only because darkness brought a sudden-death play-off between Woods and Ernie Els to an inconclusive end.
Pairings for Sunday's singles matches:
Justin Leonard (USA) v Tim Clark (RSA)
David Toms (USA) v Trevor Immelman (RSA)
Tiger Woods (USA) v Retief Goosen (RSA)
Kenny Perry (USA) v Mark Hensby (AUS)
Fred Couples (USA) v Vijay Singh (FIJ)
Scott Verplank (USA) v Mike Weir (CAN)
Jim Furyk (USA) v Adam Scott (AUS)
Stewart Cink (USA) v Peter Lonard (AUS)
Fred Funk (USA) v Michael Campbell (NZL)
Davis Love (USA) v Nick O'Hern (AUS)
Phil Mickelson (USA) v Angel Cabrera (ARG)
Chris DiMarco (USA) v Stuart Appleby (AUS)