His 6-2, 6-3, 6-7(3), 7-6(5) victory over the world No.85 booked his second Slam quarterfinal after last year’s Wimbledon.

“The only thing I understood today is the match is never done, and I almost s**t on my pants,” Cobolli said. “I'm happy, but I'm still nervous and I’ll have to recover a bit now.

“I always say that this is my favourite Grand Slam, and I love to play on clay and I love to play in France. The crowd is unbelievable. I also want to say thanks to my team... we are really happy to have the chance and the honour to play another match here, so I'm looking forward to the next one.”

Dedication to the cause could have gone seriously awry for Svajda after he scrambled unsuccessfully for a drop shot in the opening game.

A light tumble after he frantically squeezed past the umpire’s chair left him caked in clay and Cobolli was quick to come to his aid.

It was part of an inauspicious start for the American who dropped his opening serve moments later and after 43 minutes, Cobolli had ridden the momentum to the first set on the back of 14 winners and 77 per cent of first-serve points won.

Svajda arrived in Paris with just one tour-level clay-court win before cutting a path through to the second week, which included claiming his biggest career win over 25th seed Francisco Cerundolo.

This was already uncharted territory at a Slam, having only reached two US Open second rounds, and he needed to make inroads fast to extend his unexpected second-week stay.

Ratcheting up the attack, he snatched his first break to open the third and while unable to consolidate, Svajda’s third-set dominance on first and second-serve points won – 77 per cent and 64 per cent respectively – helped end his opponent’s run of 11 straight sets in Paris.

It immediately jolted the Italian into action. A blazing forehand winner – one of 41 off that wing from 57 total winners – landed Cobolli the double break, but the 24-year-old was far from home and hosed.

From 5-1 up, nerves began to take hold and Svajda’s calculated risks paid off as he amplified the pressure.

“I tried to stay a little bit positive. I was starting to be a little bit nervous, also with my team,” Cobolli said.

“So I tried to play my tennis, to play hard as possible, and I took my time also after the point. I was a little bit with less energy from the other three sets. So I think I just played my tennis without thought, and at the end, it works.”

Twice broken when serving for the match, Cobolli finally snapped a five-game streak against him on a drop-shot winner before scraping through a tense tiebreak for a shot at fourth seed Felix Auger-Aliassime or Chile’s Alejandro Tabilo.

Keen to distinguish his match nerves from any perceived tension about a wide-open men’s draw, Cobolli would not be drawn on thoughts beyond his next match.

“No, just because the match is fourth round, you serve for the match, and it's not easy, especially because I never played fourth round here,” he said.

“It's my first time, and the experience is not high. Sometimes you have to pass this moment to have more chance to be better on the next one.

“I think when the match is almost done, you start to think of it, and that's the problem I think with my character, because I don't like to think a bit.

“I just want to play, play my best tennis possible. But if I think, especially if I'm nervous, I start to play a different tennis, and of course the Chatrier is not easy for everyone. So I think also the court was tough.”