The USA fired an early warning shot to Europe ahead of next year's Ryder Cup as they came within a whisker of winning the Presidents Cup with a day to spare at Liberty National.
Holding a commanding 8-2 lead overnight, the Americans took three-and-a-half points in the morning foursomes and were on course to whitewash the afternoon fourballs until Anirban Lahiri produced two late birdies as he and Si Woo Kim won one up against Kevin Chappell and Charley Hoffman to reduce the deficit to 14 1/2 - 3 1/2.
A seventh consecutive US victory over the International side will be confirmed with their first point of the Sunday singles.
Nick Price's International side continued to struggle in New Jersey as only South African pair Louis Oosthuizen and Branden Grace prevented a clean sweep of the morning session, taking a half from Rickie Fowler and Justin Thomas.
That left the door ajar for the possibility of a first Saturday win in the tournament's history but Lahiri's late efforts kept the contest alive, theoretically at least, going into Sunday.
The only minor blemish for Steve Stricker's US side came when Jordan Spieth picked up Oosthuizen's moving ball on the 12th and the Americans were disqualified from the hole.
Australian Jason Day drove to just off the front of the green and pitched to tap-in range, with Spieth and Reed conceding his birdie putt.
Spieth and Reed both had birdie putts to come when Oosthuizen hit his eagle attempt, but as the ball passed the hole it began rolling down a hill to jeers from the home fans, prompting Spieth - knowing the Internationals were already in for their three - to pick it up while it was still moving.
The official with the match promptly disqualified the Americans from the hole, despite Day and Oosthuizen arguing against the decision, to leave the International pair one up.
However, Spieth and Reed combined for three birdies in a row from the 15th to claim a 2 and 1 success.
Daniel Berger and Thomas overcame Jhonattan Vegas and Hideki Matsuyama 3 and 2 and Brooks Koepka and Dustin Johnson were 3 and 2 winners over Grace and Marc Leishman.