Trailing by two points after the opening-morning fourballs at Le Golf National, home captain Thomas Bjørn brought wildcard picks Poulter, Garcia and Henrik Stenson into the action and the decision paid off in style.
Europe roared back at the Americans to the delight of raucous crowds at the first Ryder Cup to be played in France.
“It's hard to say it's not right at the top as a session, but then you've got to look at the other way and say this morning's session wasn't at the top,” said Dane Bjorn. “It is right at the top. When you clean-sweep, that is something that is pretty special to all those players that are out on that golf course.”
US skipper Jim Furyk left out Tiger Woods and Patrick Reed after their defeat by Francesco Molinari and Tommy Fleetwood got Europe on the board, and his players totally lost the head of steam they had built up earlier in the day.
“I think we had the momentum going into the afternoon, but we just didn't carry it in,” said Furyk. “Don't take anything away from the Europeans. They played a great session of golf from top to bottom.”
It was the first foursomes clean sweep for the hosts in Ryder Cup history, gaining revenge for the 4-0 foursomes defeat they suffered on the first day of the Americans' win at Hazeltine two years ago.
The States arrived at Le Golf National with a star-studded outfit featuring nine major champions as they look for a first win on European soil since 1993, but they were left shell-shocked after falling apart on the picturesque Albatros course.
Stenson and Justin Rose reprised their successful partnership of Ryder Cups gone by to see off Rickie Fowler and Dustin Johnson 3 and 2, while Garcia teamed up with Swedish rookie Alex Noren to crush Phil Mickelson and Bryson DeChambeau 5 and 4.
The experienced duo of Poulter and four-time major winner Rory McIlroy battled back from 2-down to beat Bubba Watson and Webb Simpson 4 and 2.
Molinari and Fleetwood grabbed their second win of the day with a 5 and 4 thumping of Jordan Spieth and Justin Thomas, as all the American pairings finished their rounds over par.
All four matches saw dominant triumphs for Europe and finished within an hour of each other.
Rose, Stenson get back together
FedEx Cup winner Rose — who had slumped to defeat by Brooks Koepka and Tony Finau earlier in the day alongside Jon Rahm — put in a solid performance with Stenson which saw them storm 5-up after 11 holes and leave Johnson and Fowler with too much to do. Rose and Stenson have now won five of seven Ryder Cup matches as a partnership.
“Henrik and I have had great vibes in this event,” said Englishman Rose.
McIlroy had struggled badly in the fourballs, failing to make a birdie or win a hole as he and Danish debutant Thorbjørn Olesen lost to Johnson and Fowler.
But, despite taking a two-hole advantage after three, Simpson and Watson reeled off five bogeys in just six holes to throw the match away.
The talismanic Poulter all but ended the encounter as a contest with a dead-eyed birdie putt on the 13th, after an incredible recovery shot from McIlroy out of thick rough.
“It's been a long time since I played a Ryder Cup,” said Poulter, who was a vice-captain in the loss at Hazeltine in 2016. “Four years is a long wait but the second I got going this morning, I felt good.”
Garcia repays Bjorn's faith
The 38-year-old Garcia had been a controversial pick by Bjørn after a poor season, but he and Noren raced into a 7-up lead over the misfiring Mickelson and DeChambeau on the front nine.
Former Masters champion Garcia has won 23.5 points since making his Ryder Cup debut as a teenager in 1999, and needs just two more to pass all-time record-holder Nick Faldo's mark of 25, but he was quick to praise Noren's
performance in his first Ryder Cup match.
“I think Alex was a rock,” said the Spaniard. “I helped him a little bit here and there and it was great to get a point.”
Spieth and Thomas were magnificent in their thrilling 1-up fourballs win over Paul Casey and Tyrrell Hatton, but off-colour against the excellent Molinari and Fleetwood.
British Open champion Molinari, as he did in the win over Woods and Reed, made the winning putt.
By AFP's Jed Court