USA hold a three-point advantage over Europe going into the final day with the hosts leading 9.5-6.5 at Hazeltine.
Rory McIlroy and Thomas Pieters had managed to get the Europeans back on level terms but the Americans once again pulled away thanks to wins from Jordan Spieth and Patrick Reed, along with Phil Mickelson and Matt Kuchar.
Lee Westwood failed to sink a three-foot putt when he and Danny Willett had the chance for a half against JB Holmes and Ryan Moore.
USA's Reed was pleased with his performance and is relishing the prospect of the final day of play at Hazeltine on Sunday.
He said: "We had a huge lead early in the first match and let it slip and I was not going to let that happen again. I live for this kind of stuff - let's go some more. I can't wait for tomorrow."
The Americans need five points from Sunday's 12 singles matches to win the Ryder Cup for just the third time in the last 23 years.