Daniil Medvedev set-up a potential US Open quarter-final showdown with world number one Jannik Sinner on Monday as both men looked to exploit the huge hole left by the shock exits of superstar duo Novak Djokovic and Carlos Alcaraz.
Medvedev, the 2021 champion in New York, outclassed Nuno Borges, who was bidding to become the first Portuguese man to make a Grand Slam quarter-final, 6-0, 6-1, 6-3.
Top seed Sinner, who won his maiden Slam at the Australian Open this year by beating Medvedev in the final, takes on Tommy Paul in the night session on Arthur Ashe Stadium.
French Open champion and women's world number one Iga Swiatek, meanwhile, stayed on course for a sixth Grand Slam title with a straight sets win over Russia's Liudmila Samsonova.
Medvedev, the only former champion left after the defeats of four-time winner Djokovic and 2022 champion Alcaraz, is in the quarter-finals for the fifth time in six years.
The world number five easily downed 34th-ranked Borges whose challenge fizzled out under the weight of 51 unforced errors while Medvedev broke serve eight times.
"I played Tommy twice this season. I beat him once but I feel as if he should have beaten me both times," said Medvedev who was also runner-up in 2019 and last year.
"I've had unbelievable battles with Jannik. It will be very physical for both of us."
Sinner, 23, faces Paul of the United States hoping to become the only man this year to reach the quarter-finals at all four Grand Slams.
The Italian made the last-eight at New York in 2022 where he squandered a match point in losing to eventual champion Alcaraz.
Paul, the 14th seed, is looking to join compatriots Frances Tiafoe and Taylor Fritz in the quarter-finals as the US looks for a first male Grand Slam champion since Andy Roddick triumphed in New York in 2003.
If Sinner gets through he will meet Medvedev for the fourth time this year.
Sinner came back from two sets to love down to defeat the mercurial Medvedev in the Australian Open final and came out on top in the Miami semi-finals.
Medvedev triumphed at Wimbledon in a five-set quarter-final.
Jack Draper became the first British man since Andy Murray in 2016 to reach the quarter-finals by seeing off Tomas Machac of the Czech Republic 6-3, 6-1, 6-2.
The 22-year-old left-hander has only dropped served once over four matches on his way to a maiden Slam quarter-final, winning 47 of 48 service games and saving 20 of 21 break points.
Draper hailed the influence of Murray, the former world number one and 2012 US Open champion, who retired from tennis following the Paris Olympics.
"He's a legend and an icon and if I have half the career that he had I will be a happy man," said the 25th seed who goes on to face Alex de Minaur.
The 10th seeded De Minaur won an all-Australian battle with Jordan Thompson 6-0, 3-6, 6-3, 7-5.
Four-time French Open winner Swiatek, the 2022 champion in New York, celebraated her 100th Grand Slam match by cantering to a 6-4, 6-1 win over 16th-ranked Samsonova.
The Pole will take on American sixth seed Jessica Pegula for a place in the semi-finals.
"There will be some long rallies and intense hitting," said Swiatek of facing Pegula who she also beat in the quarter-finals on her way to the 2022 title.
US sixth seed Pegula made the last-eight for the second time with a 6-4, 6-2 victory over Russia's Diana Shnaider.
Beatriz Haddad Maia became the first Brazilian woman to reach the quarter-finals since Maria Bueno in 1968 when she defeated 2014 runner-up Caroline Wozniacki.
The 22nd-ranked left-hander converted a third match point to defeat the former world number one 6-2, 3-6, 6-3.
She will next face 2023 semi-finalist Karolina Muchova who knocked out French Open and Wimbledon runner-up Jasmine Paolini, the fifth seed, 6-3, 6-3.
Muchova, ranked at 52, who only returned to the tour in June after 10 months out with a wrist injury, has yet to drop a set and knocked out two-time champion Naomi Osaka in the second round.
