Defending champion Carlos Alcaraz survived a second successive scare to book his place in the quarter-finals at Wimbledon.

Two days ago, he had been taken to five sets by Frances Tiafoe and very nearly faced the same against Ugo Humbert. But he raised his level late in the fourth set to win 6-3, 6-4, 1-6, 7-5.

Sets three and four were far from vintage Alcaraz as the Spaniard struggled on serve, repeatedly misjudged his shots and was repeatedly gesticulating towards his box amid the frustration.

But full credit must go to Humbert, who raised his level in the latter two sets, broke the Alcaraz serve on five occasions and threatened to pull off a seismic shock under the roof on Centre Court.

Alcaraz had struggled against a left-handed player in Jack Draper at Queen’s, the British No1 knocking him out and the Spaniard crediting that match with enabling him to get over the line against another leftie in Humbert.

Afterwards, he said: “I feel great. I think I played a really high level. I just tried to fight every ball, every point.”

Never was that truer than set point in the second set where twice he found himself on the floor in the rally only to clamber back up, win the point and roar towards the crowd, who in turn gave him a standing ovation. His own assessment of that point after the match was simply “unbelievable”.

Last year, Alcaraz seemed to get better with each round on his way to a first Wimbledon title and that appeared to be the case on Sunday as Humbert had no answer to what was coming back at him from the other side of the net early on.

The Frenchman, though, did have his chances in the second set, four break points in all, all coming in one vital hold midway through the set.

As Alcaraz broke and put himself into a two-set lead, it seemed likely it would extinguish the fire in Humbert.

But the opposite proved to be the case as he broke what turned into a surprisingly out-of-sorts opponent three times in a row.

That continued into the fourth set with all four of its opening five games proving to be breaks.

But the set and the momentum of the match again shifted with Alcaraz serving at 0-40 and 4-3 down in the set. He held and this time there was no celebration, only relief.

A stunning passing shot in game 11 proved the turning point, Humbert was broken and Alcaraz served out the match.