Taylor Fritz was simply relieved. It was almost 10.30pm; he had just survived a second, consecutive five-set, nail-biter against a 6ft 8in man with a massive serve and now, finally, he had a day off.

The American world No.5 beat Gabriel Diallo 3-6, 6-3, 7-6(0), 4-6, 6-3 in three hours and six minutes. It was his third day on court (the fifth set of his previous match had been played on Tuesday) and he was exhausted.

“Tomorrow is going to be a very light hit,” he said with a smile. “I think I’ve played a lot of tennis. I’m coming from four matches in a row in Eastbourne, one day off, a match over two days here and into this, so I’m very due a very relaxing day.

“That’s an incredibly hard match,” he said. “The fourth set – I don’t think there's much that I did wrong at all and I kind of felt like that’s the way the match was going: I was going to have to play near perfect when I got my opportunities. I’m happy to get through that.”

Diallo is sitting at No.40 in the rankings, his highest placing to date. He is only 23 and is still on his way up; to beat Fritz would have been the biggest win of his career so far. The 27-year-old Fritz has been in and around the world’s elite for years and has made it known that if he never wins a Grand Slam title, he will regret it for the rest of his life. He is clearly not afraid of putting himself under pressure.

These two arrived in town as the most successful grass court players this year. Fritz is the reigning champion of Stuttgart and Eastbourne and Diallo holds the ‘s-Hertogenbosch trophy. Both have nine match wins on the surface and both are towering figures on the court (Diallo stands 6ft 8ins and Fritz 6ft 5ins). Unsurprisingly, then, they both have a big game.

If all of that did not whet the appetite, then a quick look at the draw sheet would. In the quarter where these two combatants reside, five of the eight seeds have already left the building. As the day began, only Alejandro Davidovich Fokina, Karen Khachanov and, of course, Fritz were still standing. In theory, this was the perfect opportunity for the American.

Diallo, though, had not read that script. He, too, had seen the holes in the draw and he fancied his chances. When he skipped to a 3-0 lead, not allowing Fritz to get on the scoreboard for 15 minutes, he really fancied his chances. Another 15 minutes later, he was a set to the good.

Not that falling behind to a serving giant was going to bother Fritz; he had had plenty of practice in that department. His first round had been against Giovanni Mpetshi Perricard, who is the same height at Diallo, and went the distance. The No.5 seed was used to walking from one side of the court to the other without touching the ball (Mpetshi Perricard fired 37 aces past him). He knew to bide his time and wait for the lesser ranked man to falter.

Fritz knows that he is a good grass court player and that not many men feel as comfortable on the green stuff as him. But in eight previous visits to the All England Club, he has only managed to reach two quarter-finals.

The most heartbreaking loss was in 2022 when Rafael Nadal pushed through in five sets and then withdrew from The Championships the next day with an abdominal injury. If he had retired during their match – and Nadal was clearly struggling in the latter stages – Fritz would have been in his first semi-final. As it was, neither of them would be playing in the last four.

Wimbledon, then, has taught the American to be patient. Surely, one day, his chance will come; all he has to do is keep working and waiting. As he was waiting on Wednesday night, he could not have failed to notice a pattern emerging: if a rally broke out, Fritz tended to win it. If Diallo served and volleyed, Fritz tended to be in trouble. And if they kept thumping down service winners, aces and unreturnables, we would all be here all night.

The second set went Fritz’s way thanks to that rallying advantage – the American was rock solid from the back of the court – and the third headed to a tiebreak without a break point to be seen. Once there, Fritz did not drop a point. That was when everything stopped as the roof was closed, as darkness fell.

Back to work after that brief interruption, something had changed. There was a new glint in Diallo’s eye. After a quick chat with his coaches during the break, he had renewed aggression. He was serving and volleying. He was using Fritz’s stubborn refusal to advance from the baseline to his advantage. He was even beginning to win some of the baseline rallies. He was a break up after three games and on his way to winning the fourth set. This was a completely different match.

The fifth set is what separates the men from the boys. Diallo had only gone the distance twice before (won one, lost one) whereas Fritz had been here many times before.

That experience told as he finally broke the Diallo serve to grab a 4-2 lead and from there, he never looked back.