Carlos Alcaraz, Sinner into Wimbledon quarters; Dimitrov injured - ESPN

Defending Wimbledon champion Carlos Alcaraz and world No. 1 Jannik Sinner both handled challenges Sunday to reach the Wimbledon quarterfinals and move one match away from another high-stakes semifinal.

Alcaraz came up with the big shots when it mattered most to hold off Ugo Humbert in a 6-3, 6-4, 1-6, 7-5 win on Centre Court. Sinner withstood the big serving of No. 14 Ben Shelton for a 6-2, 6-4, 7-6 (9) victory.

To reach the semifinals, Sinner will face Daniil Medvedev. The No. 5 seed advanced when No. 10 Grigor Dimitrov was forced to withdraw due to injury while trailing 5-3 in the first set.

Alcaraz beat Sinner in five sets in the French Open semifinals in June en route to his first title at Roland Garros, and the two would meet again in the last four if they win their next matches.

On Sunday, Alcaraz seemed to have his match all but won when he clinched the second set by chasing down several seemingly out-of-reach shots on set point, even falling over after hitting one forehand and quickly getting back up to get to the next ball.

Asked to describe his play on that point, Alcaraz just said: «Unbelievable, I guess.»

But Humbert nearly staged a surprising comeback and threatened to take the match into a fifth set when he held three straight break points for a 5-3 lead in the fourth.

Alcaraz came back to win that game with the help of a couple of aces then broke for a 6-5 lead by hitting a deep forehand winner.

He set up match point with one of his delicate forehand drop shots and converted it with a service winner.

«I felt great playing today. I think I played at a really high level,» said Alcaraz, who will next play the winner of the match between No. 12 Tommy Paul and Roberto Bautista Agut.

Shelton started aggressively