Defending champion Carlos Alcaraz and world number one Jannik Sinner stayed on track for a blockbuster Wimbledon showdown after both players reached the quarterfinals on Sunday.

French Open champion Alcaraz, who is looking to defend his Wimbledon trophy and complete what is dubbed the "Channel Slam" in reference to the English Channel that separates Britain and France, battled past Metz-born Ugo Humbert 6-3, 6-4, 1-6, 7-5.

"I think I'm getting better and better every match that I'm playing," said Alcaraz, who was happy to avoid another five-set tussle after being taken the distance by the USA's Frances Tiafoe in the previous round. "I'm feeling really comfortable on the court and hitting good points, good shots."

No. 12 seed Tommy Paul of the USA set up a last-eight meeting with the 21-year-old Spaniard after the Queen's Club champion downed Spain's Roberto Bautista Agut 6-2, 7-6(3), 6-2.

Italy's Sinner, who could face Alcaraz in the semifinals in a rematch of their Roland Garros meeting, was equally impressive in his 6-2, 6-4, 7(11)-6(9) win over 14th seed Ben Shelton.

"I'm happy how I handled the situation," said Sinner, who neutralized the feisty American's big serves to prevail. "It was obviously very, very tough to play against him, one of the best servers we have on Tour, very aggressive player. I'm happy how I returned today. Yeah, I think that's for sure one of the keys today."

The 22-year-old will next meet fifth seed Daniil Medvedev, who he defeated in January to win his maiden Grand Slam title at the Australian Open.

Russia's Medvedev progressed when Bulgarian 10th seed Grigor Dimitrov retired from their clash with a groin injury while trailing 5-3 in the first set.