Carlos Alcaraz inched a step closer to defending his Wimbledon title with a hard-fought victory over Ugo Humbert.

The 21-year-old Spaniard held off a late charge from 16th seed Humbert to win 6-3 6-4 1-6 7-5 and move into the last eight at SW19.

It took Alcaraz's winning streak at Grand Slams to 11 following his French Open triumph last month.

"I feel great playing today, I think I played a really high level," he said.

"Playing a leftie, I try not to think about it and play my own game."

Alcaraz will next face compatriot Roberto Bautista Agut or American 12th seed Tommy Paul, the Queen's Club champion.

Meanwhile, world number one Jannik Sinner defeated American 14th seed Ben Shelton 6-2 6-4 7-6 (11-9).

Shelton, who won in five sets in his first three rounds, had four set points in the third-set tie-break.

Sinner, 22, will play fifth seed Daniil Medvedev or 10th seed Grigor Dimitrov next.