Jannik Sinner and Iga Swiatek sprint into US Open fourth round

Top seeds untroubled in New York to advance to the last 16 without dropping sets in the third round

Jannik Sinner cruised past Christopher O'Connell to reach the US Open last 16. AFP

Top seeds Jannik Sinner and Iga Swiatek made comfortable progress through to the US Open Round of 16 on Saturday as the men's world No 1 easily avoided a similar fate to Novak Djokovic and Carlos Alcaraz.

Australian Open champion Sinner raced past 87th-ranked Christopher O'Connell 6-1, 6-4, 6-2. The 23-year-old Italian's win came a day after four-time and defending champion Djokovic was sent spinning to his earliest loss in New York in 18 years by Alexei Popyrin.

One day earlier, 2022 winner Alcaraz was defeated in the second round by Dutch journeyman Botic van de Zandschulp.

"I knew I had to play very solid. My serve worked well so I am happy with my performance," said Sinner after firing 15 aces in his 46 winners past outclassed O'Connell of Australia.

Sinner did not face a single break point in his one-hour 53-minute victory which took him into the last 16 for a fourth successive year.

"There have been some upsets in the tournament so let's see what's coming. I'm happy to still be here and play as many matches as possible," added Sinner whose comfortable afternoon on Arthur Ashe Stadium saw tennis legend Serena Williams amongst the spectators.

Sinner, who entered the US Open amid a doping controversy having escaped a suspension earlier in the year, will take on 14th seed Tommy Paul for a quarter-final place after the American defeated Canadian qualifier Gabriel Diallo in four sets.

There were 14 breaks of serve in that tie with Diallo, ranked a lowly 143 in the world, undone by 77 unforced errors.

Swiatek stays on course for second US Open title

Four-time French Open champion Swiatek was equally dominant as Sinner as the top-seeded Pole eased into the fourth round with a 6-4, 6-2 victory over Russia's Anastasia Pavlyuchenkova.

The 23-year-old will face another Russian, Liudmila Samsonova, for a quarter-final place.

"I like the night sessions but it's noisy so I need to focus on my job and stay inside my bubble," said Swiatek, who shot a long hard stare at her opponent when a ball was speared towards her early in the second set.

With Djokovic and Alcaraz heading home to Europe, Daniil Medvedev finds himself as the only former champion left in the men's tournament.

The Russian, seeded fifth, swept past Flavio Cobolli, the world No 31 from Italy, 6-3, 6-4, 6-3.

Medvedev famously shattered Djokovic's bid for a rare calendar Grand Slam when he captured the 2021 title in New York.

"I said before the match that for me the upsets don't matter. The conditions here are tricky and the favourites have fewer margins," said Medvedev after making the fourth round for the sixth straight year.

He will next face unseeded Nuno Borges of Portugal, who saved three match points in a five-set triumph over Czech teenager Jakub Mensik.

Britain's Jack Draper reached the last 16 for a second successive year by defeating Alcaraz's conqueror Van de Zandschulp 6-3, 6-4, 6-2.

There will be at least one Australian man in the quarter-finals with Alex de Minaur and Jordan Thompson setting up a fourth-round clash.

De Minaur defeated an ailing Dan Evans 6-3, 6-7, 6-0, 6-0 with the Briton hardly able to walk in the closing stages, a legacy of playing the longest match in US Open history in the first round.

Thompson defeated Italy's Matteo Arnaldi in straight sets.

Paolini extends Grand Slam form

Meanwhile, 2023 semi-finalist Karolina Muchova, who knocked out two-time champion Naomi Osaka in the second round, cruised through by beating Anastasia Potapova 6-4, 6-2.

She next faces French Open and Wimbledon runner-up Jasmine Paolini, the fifth-seeded Italian, who beat Yulia Putintseva 6-3, 6-4.

Paolini has now made the fourth round of all four Slams this year having previously never got beyond the second round in 16 attempts.

"I'm a fan of her (Muchova). I really love how she plays. She can play every shot, slice, volleys, serve and volleys. She's a very complete player," said Paolini.

US sixth seed Jessica Pegula made the second week for a third successive season by defeating Jessica Bouzas Maneiro 6-3, 6-3.

Pegula next faces Diana Shnaider, the 18th-seeded Russian who made the fourth round of a Slam for the first time by seeing off 37-year-old Sara Errani in straight sets.

Caroline Wozniacki, the runner-up to Serena Williams 10 years ago, defeated French qualifier Jessika Ponchet for the loss of just five games.