Serena Williams’ quest for an elusive 24th major championship continued with a 6-2 6-4 win over Margarita Gasparyan to advance to the third round of the US Open.

Williams improved her career record to 20-0 in the second round at Flushing Meadows on Thursday and will play Sloane Stephens in the next round.

Wearing crowns on her sneakers, Williams had 27 winners and seven aces to put away Gasparyan.

Williams has won 23 grand slam singles titles, the most in the professional era and one shy of Margaret Court’s mark of 24.

She’s won the US Open six times and finished runner-up each of the last two years. Her opening win was her 102nd in the tournament, breaking a tie with Chris Evert for most in the professional era, which started in 1968.

But with the field decimated by withdrawals including that of world No.1 Ashleigh Barty, and coupled with the shock defeat suffered by top-seed Karolina Pliskova on Wednesday, Williams has an increasingly clear run to a seventh Flushing Meadows crown.

Stephens beat Olga Govortsova 6-2 6-2 to advance.

“I’m just happy to get through and try to focus on the next round,” said Williams.

“Sloane is such a good player, she plays so smooth. She looks like she is not taking a lot of energy and then suddenly bam! Five winners.”

Earlier, unseeded Bulgarian Tsvetana Pironkova knocked out former Wimbledon and French Open champion Garbine Muguruza.

The 32-year-old, who gave birth to a son in April 2018 and is playing in her 12th Open but her first tournament since Wimbledon in 2017, prevailed 7-5 6-3 over the Spanish 10th seed.

Pironkova has no world ranking because of her lay-off, but she was a 2010 Wimbledon semi-finalist, and the victory was her 22nd against a top-20 player.

“Before it was almost like a life and death situation for me to win a match. Right now it’s not really like that. It’s enjoyment to be on the court.

“I was moving well and hitting the ball well. Why not win?”

Also out is no.9 seed Johanna Konta, beaten 2-6 7-6 (7-5) 6-4 by world No.77 Sorana Cirstea.

Konta, a quarter-finalist in New York last year, battled for two hours and 50 minutes against Cirstea, who claimed her first top-20 victory since May 2019, to book a third round meeting with Karolina Muchova.

Cirstea punished Konta’s second serve throughout the match, limiting her opponent to just a 34 per cent success rate on that shot. The 30-year-old Romanian fired eight aces and was an impressive 13/16 at the net.

“Surprised? No. Frustrated? Obviously,” said the 29-year-old Konta when discussing her upset.

Australian Open champion Sofia Kenin advanced to the third round by beating unseeded Leylah Fernandez 6-4 6-3.

Madison Keys once again wasted no time on court, defeating Spain’s Aliona Bolsova 6-2 6-1 in less than an hour.

Keys, runner-up in 2017 and a semi-finalist in 2018, defeated Timea Babos in 55 minutes on Tuesday.

Amanda Anisimova won a match-up of American teenagers, rallying past wild card Katrina Scott 4-6 6-4 6-1.