Serena Williams has moved another step closer to a record-tying 24th career Grand Slam title with a comfortable 6-3 6-2 victory over Czech Karolina Muchova to reach the last 16 at the US Open.

Wimbledon quarter-finalist Muchova held serve for an early 3-2 lead in her first career meeting with Williams on Friday, but the six-times champion cranked up the pace and won the next seven games to take over the match.

Williams took advantage of a poor serving performance by Muchova and broke her opponent five times, including in the final game where she sealed the victory with when the Czech sent a backhand long.

Up next for Williams will be Croatian 22nd seed Petra Martic, who beat Latvian Anastasija Sevastova earlier on Friday.

If she wins that match, she could face world No.2 Ashleigh Barty, who passed the sternest test yet of her US Open title credentials by beating Maria Sakkari 7-5 6-3 to equal her best-ever run in New York.

Sakkari, seeded 30th, had beaten Barty last year in Indian Wells but Australia’s world No.2 played the match on her terms from the outset.

The French Open champion fired down 10 aces and dropped serve only once while breaking Sakkari four times during the 87-minute work-out.

Barty will face either China’s 18th seed Qiang Wang or unseeded Frenchwoman Fiona Ferro next on Sunday, with the winner likely strike Williams in the last eight.

Meanwhile, Czech third seed Karolina Pliskova was also tested on a hot day by Tunisia’s Ons Jabeur before triumphing 6-1 4-6 6-4 in a match that lasted two hours and eight minutes.

Jabeur took a medical time out midway through the match to have a knee injury looked at before storming back to claim the second set, but Pliskova held on in the final set to move into the fourth round, converting seven break points in the match.

Briton Johanna Konta also progressed to the next round after beating China’s Zhang Shuai 6-2 6-3.