Alex de Minaur and Jordan Thompson will joust for a US Open quarterfinal spot as Australia's extraordinary assault on the season's last grand slam continues.

De Minaur wore down veteran British marathon man Dan Evans 6-3, 6-7 (7/4), 6-0, 6-0 to clinch a last-16 berth for a fifth consecutive slam after the seed-slaying Thompson claimed yet another big scalp on day six in New York.

After sending world number seven Hubert Hurkacz packing in round two, Thompson took out 30th seed Matteo Arnaldi 7-5, 6-2, 7-6 (7-5) to storm into the fourth round at Flushing Meadows for a second time.

Thompson promptly branded the high-stakes match-up with his Sydney mate "unreal".

"For sure an Aussie in the quarters. I hope that it is me," he beamed.

With Alexei Popyrin basking in the glory of his stunning defeat of defending champion Novak Djokovic, Australia has converted its biggest US Open contingent in 43 years into three players in the men's last 16 for the first time this century.

And after shifting up a couple of gears to produce his most impressive tennis of the tournament, de Minaur suddenly looks like a man on a mission again.

Playing his first singles event since withdrawing from Wimbledon with a hip injury, de Minaur felt he was only functioning at 85 per cent of his physical capacity in the first two rounds.

But the world number 10's movement was lightning in a quality contest with Evans, who has made a habit of knocking out Australians in New York.

De Minaur, though, avoided enduring the same Flushing Meadows fate as Bernard Tomic, James Duckworth and Popyrin three years ago.

He ran Evans ragged on Louis Armstrong Stadium, four days after the 34-year-old featured in a 5-hour, 35-minute epic, the longest US Open match in history, with Karen Khachanov.

Thompson will take a power of stopping, though, when the Australians collide on Monday (Tuesday AEST).

Also playing the tennis of his life, having won his maiden ATP title this year in Los Cabos and made the final in Atlanta, the proud Paris Olympian has now matched his career-best grand slam run from the 2020 US Open.

Yet to drop a set this campaign, Thompson fell behind 4-2 in the third against Arnaldi, a 2023 Italian Davis Cup winner widely considered one of the brightest young stars in tennis.

But, as he does, Thompson went straight back to work, breaking Arnaldi in the seventh game and recovering from 3-0 down in the third-set tiebreaker to seal victory after 2 hours, 33 minutes.

"It was a great match from me. The third round is pressure. I have not been there too much in my career," he said.

"I was getting a little bit agitated there but I dealt with it really well and came out on top. It is really pleasing to win under lights in New York on a Saturday night."

The 30-year-old is set to claim a new career-high ranking inside the world's top 30 and believes he is only now starting to peak.

"It is hard to argue with. I feel like I am getting better as I get older," Thompson said.

"It is definitely the best I have been playing in my career and my results and ranking dictate that."

World number one Jannik Sinner's bid for a second grand slam title continued to gain momentum as he thumped Christopher O'Connell 6-1, 6-4, 6-2 to reach the fourth round at the US Open on Saturday.

Sinner, who is controversially playing in New York after avoiding sanction following two failed drug tests, took an hour and 53 minutes to bundle out his 87th-ranked opponent.

The Italian made slow starts in his opening two matches at the US Open but he shot out of the blocks on Arthur Ashe Stadium court for a 5-0 lead before taking the first set on serve.

Australian O'Connell provided a degree of resistance in the second set, but Sinner broke early to take a 2-1 lead and went on to clinch the set with a vicious cross-court forehand winner.

Sinner continued to pepper O'Connell with winners, taking his tally up to 46 as he broke twice in the final set to wrap up the win.

Australian Open champion Sinner's strongest weapon in the victory was his flawless serve, firing 15 aces and denying O'Connell any break points across the three sets.

"For sure today was a great match," Sinner said.

"I knew I had to play very solid throughout the whole match. The serve was working well today. I'm happy about my performance."

O'Connell, who had lost all eight of his previous meetings with top-10 players, looked powerless throughout as his bid to reach the fourth round of a grand slam for the first time failed.

Sinner faces either 14th-seeded local hope Tommy Paul or Canadian qualifier Gabriel Diallo in the fourth round.

The Italian will have been happy to get through the test of O'Connell after seeing two of his biggest rivals for the title at Flushing Meadows fall by the wayside this week, with both Carlos Alcaraz and Novak Djokovic knocked out in the first week.

It marks the first time since 2000 — and only the second time in the Open era, which dates to 1968 — that two of the top three men's seeds were knocked out during the first week in New York.

"Anything can happen in this sport," Sinner said.

"I focus on my side of the net and appreciate every moment on court.

"It's all about being here and playing as many matches as possible."

Djokovic's defeat also carries significance as making this the first season since 2002 in which no member of the so-called Big Three of men's tennis — Djokovic, Rafael Nadal and Roger Federer — will win a grand slam.

Just one previous men's champion remained in the bracket: 2021 winner Daniil Medvedev.

Meanwhile, Britain's Jack Draper dispatched Alcaraz's conqueror, unseeded Botic van de Zandschulp, 6-3 6-4 6-2 to reach the last 16. Draper will next face Czech Tomáš Macháč.

ABC/wires