Halfway through Saturday afternoon, something unexpected happened: the United States finally showed up at this Ryder Cup. And as the top of the scoreboard turned red, and the chants of “U-S-A! U-S-A!” climbed in volume and intensity, Rory McIlroy and Patrick Cantlay became locked in a battle for the ages. It was one that raged on the course – and, dramatically, later in the car park too.

Because of the characters involved, a fourballs match featuring McIlroy and Matthew Fitzpatrick against Cantlay and Wyndham Clark always promised spice. But with the US team sensing a chance to slice into Europe’s lead as the match headed down the 18th, it became far more heated and visceral than that.

And the lingering tension finally boiled over when Cantlay’s caddie, Joe LaCava, celebrated his man holing from 43ft right in front of the line where McIlroy had a putt to halve the match. Shouts were heard. Fingers pointed. The anger on Europe’s side was palpable – and understandable.

There were echoes here of Brookline in 1999 when the US team celebrated Justin Leonard holing from long range when José María Olazábal was still to putt. Later, McIlroy was also seen pointing his finger at Justin Thomas’s caddie, Jim “Bones” Mackay, in the parking area, while Shane Lowry and Justin Rose also looked distinctly unimpressed.

This Ryder Cup had long needed a bit of excitement – and it certainly got that. And with Cantlay and Clark’s victory, it also now has an outside chance of a contest. The US team now trail by 10½ to 5½. Suddenly Sunday’s singles carry a small element of jeopardy.

The tension was already clear as the players walked to the 14th tee. McIlroy was greeted with huge cheers. Cantlay, meanwhile, was bombarded with chants of “Where’s your hat, Patrick?” – a reference to the rumour that he was apparently angry at not getting paid to play at the Ryder Cup and was refusing to wear headgear.

At this point the contest had come down to McIlroy v Cantlay, hero v villain, ultimate team player against a man rumoured – and denied – to have caused a split in the US locker room.

Such was the tension that Clark whacked his ball out of bounds – before Fitzpatrick did the same. Meanwhile Cantlay was on the fairway, ready to twist the knife. But cometh the hour, cometh McIlroy – or so it seemed.

First he pounded a 376-yard drive down the middle. Then, after a textbook sand wedge, came a nerveless putt to put Europe one up with three to play. However Cantlay – who is nicknamed “Patty Ice” for a reason – refused to go away.

First he made a 10ft putt on the 16th to halve it with a birdie. Then he levelled the match with a birdie from 9ft on the 17th. Before, finally, a stunning 43ft putt gave him another birdie – and the US victory.

“I wasn’t really thinking at the moment,” explained Cantlay afterwards. “It was just raw emotion. I was just feeling it. It felt like the group birdied darn near every hole on the back nine, and it felt like every putt was do-or-die.”

As he celebrated a hat-trick of birdies, the US players waved their hats in delight. However Cantlay later denied that he had not worn a hat in protest at not getting paid, pointing out that he had done the same at the last Ryder Cup. “It just doesn’t fit,” he added, as he rejected rumours of a split in the US team after their disappointing first day. “It is as simple as that. That is all it is.”

Meanwhile, McIlroy, understandably, looked gutted at not being able to pull out a win or tie at the death. And he was clearly furious with how the Americans celebrated at the end, with some choice words exchanged between Shane Lowry and LaCava too. But he insisted that the incident would only fire the Europeans up.

“They played a great match,” he said. “And, yeah, a few scenes there on 18 and just fuel for the fire tomorrow.”

However the Northern Irishman can certainly hold his head up high having won three points from four matches – including a 2&1 victory with Tommy Fleetwood over Jordan Spieth and Justin Thomas on Saturday morning.

That is an especially significant achievement given that McIlroy was in tears after Europe were thrashed at Whistling Straits two years ago because he felt he had let his teammates down.

As the skies over Rome began to darken, the US captain, Zach Johnson, insisted he was a big believer in momentum, in a way that made it sound like it could swing back and forth like a grandfather clock.

Cantlay, too, senses an opening. “We’ve been a little under the weather this week,” he said. “But we finally have a moment we can celebrate a little, and we’re going to take that opportunity and try to turn it into some momentum for tomorrow. Hopefully, we have a ray of light and we can build on this session and try and pull off a big victory.”

Perhaps come Sunday night we will all be talking about the Miracle of Marco Simone. But right now this is still Europe’s match to lose.