Spanish world number one Alcaraz silenced a partisan Melbourne crowd in brushing aside home hope Alex de Minaur 7-5, 6-2, 6-1 at Rod Laver Arena.

The 22-year-old Alcaraz is yet to drop a set as he arrows in on a first Australian Open crown.

"I'm just really happy how I'm playing every match, each round my level is increasing," he said, in a warning to his rivals.

"Today I felt really comfortable, playing great tennis that I am really proud of," added Alcaraz, who had never previously gone beyond the quarter-finals in Australia in four previous visits.

The Australian Open is the only Grand Slam that Alcaraz has not won.

Should he beat Zverev and then win Sunday's final, he would surpass compatriot and legend Rafael Nadal as the youngest man to win all four majors.

Nadal was 24 when he did it.

In a statement of his own, Zverev said he was playing without pain for the first time in 12 months after last year's runner-up blasted past young American Learner Tien.

Zverev sent down 24 aces in a 6-3, 6-7 (5/7), 6-1, 7-6 (7/3) victory.

World number three Zverev is desperate to finally win a Grand Slam at age 28, having lost three major finals including being well beaten in last year's title decider by Jannik Sinner.

The German's 2025 season fell away after that, winning just one title in an injury-hit campaign and he also struggled with his mental health, taking a one-month break after losing in the first round at Wimbledon.

"The last 10 days I felt healthy, which is very nice, and pain-free, which I haven't felt in a long time. Probably in 12 months," he said after dismantling Tien.

- Gauff's epic racquet smash -

Coco Gauff folded in 59 error-strewn minutes as Svitolina set up a semi-final against Sabalenka.

Belarusian world number one Sabalenka tamed 18-year-old American Iva Jovic 6-3, 6-0 in 38C temperatures on Rod Laver Arena.

In the evening, with the roof on because of the suffocating heat, 12th seed Svitolina stunned third seed Gauff 6-1, 6-2.

Television images showed Gauff repeatedly smashing her racquet in the bowels of the stadium afterwards.

The Ukrainian, who is on a 10-match win streak after a title-winning run at Auckland this month, added: "It means the world to me."

Svitolina said she hopes her stunning upset will bring "a little light" to her fellow Ukrainians during a bitter winter under attack by Russia.

For two-time Grand Slam winner Gauff, a decade younger at 21, it was more Melbourne misery.

She has still never gone beyond the semi-finals and the nature of the loss will sting.

Gauff's serve deserted her, broken four times in the first set and twice in the second to leave her title aspirations in tatters.

She was not amused to learn that her epic racquet smash was caught by television cameras.

"I tried to go somewhere where they wouldn't broadcast it, but obviously they did," she said.

"So maybe some conversations can be had because I feel like at this tournament the only private place we have is the locker room."

In the first action of the day, Sabalenka closed in on a third Melbourne crown in just four years.

Having been stunned in last year's final by the American Madison Keys, the hard-hitting Belarusian said it was "trophy or nothing" after muscling past the supremely talented Jovic.

The quarter-finals conclude on Wednesday, with 10-time Melbourne champion Novak Djokovic and title-holder Jannik Sinner in action.

Djokovic faces Italian fifth seed Lorenzo Musetti and Sinner plays Ben Shelton of the United States.

In the women's draw, Jessica Pegula and Amanda Anisimova meet in an all-American affair and second seed Iga Swiatek faces fifth seed Elena Rybakina.

Temperatures are scheduled to be considerably cooler.