With Jon Rahm and Tyrrell Hatton beating Scottie Scheffler and Sam Burns 4&3 and Viktor Hovland and Ludvig Aberg also winning 4&3 against Max Homa and Brian Harman, the Irish duo came good in the last two matches.
Lowry and Sepp Straka had to dig deep to put away Rickie Fowler and Collin Morikawa 2&1 after seeing a four-up lead at the turn shrink to two-up with two to go.
“It’s huge,” a delighted Lowry said. “We’re off to a great start this morning. We just need to keep the foot down. I think myself and Sepp gelled well today, I’m very happy out there with him and I enjoyed myself.
“We’ve probably known for maybe a couple of weeks so we might work this morning together. And you know, we play the same golf ball and we use the same stuff.
“So kind of made sense. We were similar type people. But I’m a bit far more fiery than him. Sepp is pretty laid back but we just we enjoyed it out there.
“I felt like we played some good golf. We dodged a few bullets out there especially, around 11 and 12 but you know, you’re going to have that in matchplay and you just have to dig deep and we did.
“I would have liked to close out the match earlier, because we had good chances but it was nice to put a point on the board for Europe.”
McIlroy and Tommy Fleetwood — dubbed FleetwoodMac — then complete the route by handing Patrick Cantlay and Xander Schauffele their first defeat in six matches for the USA in Presidents and Ryder Cups with a 2&1 win.
Luke Donald’s troops never trailed in any of their matches and swept the opening session of the Ryder Cup for the first time.
According to statistician Justin Ray, it’s just the second instance of one side sweeping the first session of the Ryder Cup with no matches reaching 18 since the Americans did it in 1975.
Cantlay and Schauffele battled back from two down to one down three times before McIlroy ripped his tee shot to 30 inches at the 206-yard 17th to set up a winning birdie for Fleetwood.
“It’s been an unbelievable session,” McIlroy said. “We switched the format this year to go foursomes first because statistically that’s our better session. And all week, all we’ve been talking about is getting off to fast starts.
“Playing three-hole matches in practise, three holes, go again, three holes, go again, something that Luke’s drilled into us.
“We were ready to go from the first tee shot and you can see in how everyone played.
“I’m so proud of this man alongside me. He can play with anyone. I’m just so happy that he’s my partner this week and so happy to get a point on the board for Europe.”
As for his shot to the 17th, McIlroy said: “I have hit a lot of good shots in my time. That’s right up there.
“I didn’t know how close Patrick had hit his but I just wanted to give Tommy a chance to at least stay one-up going down the last. I was pretty certain we weren’t going to go down the last, but if I keep hitting iron shots like that, then I’m going to have a pretty good week.”
At the top of the order Rahm and Hatton were an estimated six-under as they cruised to a 4&3 win over world number one Scheffler and rookie Burns.
“I’ve had a good feeling about Tyrrell all along,” said Rahm. “Last time we played together it really felt good, and it was good to come out here and perform the way we did.
“It’s an incredible foursomes match and we played as confident as two people can play, and it was a beautiful one.”
He added: “I told Tyrrell, usually the feelings you have down the stretch in a tournament I had hitting my first warm-up put at 6.20 in the morning in the dark, and it increasingly got higher until we hit that tee shot on the first hole.”
Hovland was the strongman alongside rookie Ludvig Aberg, chipping in at the first to get them off to the perfect start as they went on to beat Max Homa and Open champion Brian Harman 4&3.
The Americans battled back from two down after two to level after four but they lost the fifth, sixth and ninth to turn three down before Europe extended their advantage to four up after 14 holes before closing out the match at the next.
“The crowds were unbelievable here today,” Aberg said. “And we could really feel that support and that’s what we need to keep winning points here in Rome, so it was a lot of fun today.”
Hovland added: “It was such a big difference compared to Whistling Straits. Normally I keep my head down and just play, but I’m trying to really get the crowds going and just use them because they want you to play well and they want to support you. So it was such a good start, and we’re going to keep it going.”
Europe won 22 holes to just 10 for the Americans who were never up in any match.
