Should Alcaraz progress to the last four, a semi-final against Alexander Zverev may await.
The German third seed, who ended the hopes of Great Britain’s Cameron Norrie in round three, impressed in a 6-2 6-4 6-4 victory against 18th seed Francisco Cerundolo of Argentina.
Zverev, who was beaten by Jannik Sinner in last year’s Australian Open final, said he is “as healthy as he has been for the past 12 months” as he chases a maiden Grand Slam title.
In last year’s majors, he followed his runner-up finish in Melbourne with a quarter-final at the French Open, a surprise first-round exit at Wimbledon and a third-round loss at the US Open.
“I had a lot of issues with my body and a lot of injuries that prevented me from playing 100%,” said the 28-year-old. “I played through them but I was not really feeling great.
“When I’m healthy, I’m happy on the court and everything becomes a bit easier. I don’t want to jinx it but hopefully we have three more tough matches and hopefully I can stay that way.”
Zverev’s next opponent will be American 25th seed Learner Tien, who overcame an early nosebleed to reach the last eight of a Grand Slam for the first time in his career.
The 20-year-old put together a run of 11 successive games in a crushing 6-4 6-0 6-3 win against former US Open champion Daniil Medvedev, who – playing in his 35th Grand Slam tournament – was on the wrong end of a 6-0 set for the first time in a major.