Collin Morikawa delivered the winning half point when he tied his match with Viktor Hovland.
World number two Dustin Johnson beat Paul Casey 1-up to become the first American since Larry Nelson in 1979 to go five-from-five.
“Speechless,” US captain Steve Stricker said as his team was closing in on an historic points total. “They had a mission this week and you could tell. This is a new era for USA golf.”
Morikawa, who won his second major title at the British Open this year, had assured the US of victory with a brilliant birdie at the par-three 17th, where he blasted his tee shot to three feet, going 1-up with one to play to assure the US would take at least half a point from the match.
He missed a six-footer at 18 to win the match outright, but the American celebrations were already underway.
“It means so much,” Morikawa said. “To clinch this and bring the Cup back, it feels so good. We knew we had a very strong team. (That) means nothing when you get to the first tee.”
With the United States needing just 3.5 points from the 12 singles matches to secure the Cup, Scottie Scheffler, a Ryder Cup rookie with the lowest ranking in the US team at 21 in the world, opened the floodgates when he took out world number one Jon Rahm 4&3.
Rahm, who had excelled all week amid Europe’s overall struggles, became just the third world number one to lose a Ryder Cup singles match.
“I just kept the pressure on,” said Scheffler, who won the first four holes with birdies and was never less than 3-up after that.
Rory McIlroy had gained the first point of the day with a 3&2 victory over Olympic champion Xander Schauffele, but his first win of the week was no cause of celebration as he contemplated the flood of red on the scoreboard.
“(I’m) incredibly proud to be a part of this team,” McIlroy said, his voice cracking. “I’ve been extremely disappointed that I haven’t contributed more for the team.
“I realize it’s the best event in golf, bar none.”
Patrick Cantlay, the US PGA Tour’s player of the year and FedEx Cup playoff champion, polished off European rookie Shane Lowry 4&2 to push the US points total to 13.
Bryson DeChambeau followed with a 3&2 victory over Sergio Garcia, the Spanish Ryder Cup great who this week took his tally of match wins to a record 25.
DeChambeau’s power proved too much for Garcia. The American set the tone at the first hole, driving the green at the par-four and striding off the tee to wild cheers with his driver held aloft.
He won the hole with a 41-foot eagle putt and led the rest of the way.
Lowry, the 2019 British Open champion, had taken a 1-up lead over Cantlay with a birdie at the par-5 second, but Cantlay roared away from there.
The American won four straight holes for a 3-up lead, and didn’t trail again, winning the last three holes for the convincing score.
Cantlay, who won four US PGA Tour titles this year, said his first Ryder Cup experience was “definitely different” and he hoped he and the rest of the youthful team could make a statement as the looked forward to years of competing in the trans-Atlantic match play contest.
“I woke up this morning and I was telling guys lets try to get to 20 points,” Cantlay said. “This is going to be the next era of Ryder Cup Team for the US side.”
Just 19 would be a record. No team since the format changed in 1979 to include players from continental Europe as well as Britain and Ireland has amassed more the 18.5 points.
Nevertheless, Cantlay’s wish for 20 didn’t seem far fetched.
No sooner had Morikawa’s match wrapped up than four-time major winner Brooks Koepka completed a 2&1 victory over Bernd Wiesberger and Justin Thomas beat Tyrrell Hatton 4&3.
Ian Poulter notched another win for Europe, beating Tony Finau 3&2, but three late-finishing matches had the US leading in two and one tied. (AFP)