A fired-up United States team erased some of their recent Ryder Cup pain by storming ahead by 5-½ points to 2-½ over holders Europe at Valhalla Golf Club on Friday.
Two points clear after the morning's foursomes, the hosts pressed home their advantage late in the afternoon fourballs to tighten their grip amid a flurry of high-fives and fist pumps.
It was the first time the Americans had led after the opening day since Oak Hill in 1995 and their biggest advantage going into day two since The Greenbrier in 1979 when they were ahead by the same margin.
"I was just real proud of everybody," a beaming US captain Paul Azinger said of his team.
"It could have gone either way today but there were some nice comebacks. They just played really well. Everybody kind of stayed on point, stayed in the present and just kept going."
Although Europe clinched their first full point when Britons Ian Poulter and Justin Rose crushed Ben Curtis and Steve Stricker 4&2, Justin Leonard and Hunter Mahan eased past Spaniards Sergio Garcia and Miguel Angel Jimenez 4&3 soon afterwards.
Leonard, making his first Cup appearance since the US last triumphed with a come-from-behind success at Brookline in 1999, chipped in for birdie at the 15th to secure the win.
Phil Mickelson and energised rookie Anthony Kim came from one down after 12 holes to beat Irishman Padraig Harrington and Britain's Graeme McDowell two up after a fluctuating battle.
In the bottom match, Kentucky native JB Holmes and Boo Weekley squandered a one-hole lead playing the last to halve with Britain's Lee Westwood and Dane Soren Hansen.
Both Holmes and Weekley drove into water off the tee, effectively handing the Europeans a half-point on a platter and allowing Westwood to stretch his unbeaten Cup run to 12 matches.
The fiery display by Mickelson and Kim epitomised the American Cup revival as they overcame Harrington and McDowell with a strong finish.
"We played with a lot of heart and emotion," said Mickelson, who rolled in a 30-foot birdie putt at the 17th to put the duo one up. "I love playing with this guy. Anthony has got this youthfulness to him and he has a lot of game.
"It's great for us to get off to a good start because it gets the crowd involved and excited and it gives us energy; we feed off of that. We fought hard and we were able to come back."
The Americans, bidding to end a run of five defeats in the last six matches, had mounted a gritty fightback in the morning to win the opening Cup session for the first time in 17 years.
Leonard and Mahan drew first blood with a 3&2 victory over Britain's Paul Casey and Swede Henrik Stenson after recovering from a bogey-bogey start.
Stewart Cink and Chad Campbell came from one down after 12 holes to scrape past Poulter and rookie Rose one up before Mickelson and Kim halved a tight tussle with three-times major winner Harrington and Swede Robert Karlsson.
In the final match of the morning, European heavyweights Garcia and Westwood fought back from two down with two to play to finish all square with local favourite Kenny Perry and Jim Furyk.
Garcia, an inspirational figure for Europe since his Cup debut in 1999, extended his unbeaten record in foursomes matches to 8-0-1 (win-loss-half).
Although disappointed to trail the Americans by three points going into the second day, European captain Nick Faldo was proud of his team's gritty display at Valhalla.
"That was a great, great last hour of golf and to get half a point in the very last match was really great for the team morale," he said.
"Obviously we are down in points but we are up in spirit."