Serena Williams stormed into the third round of the US Open on Wednesday, defeating second seed Anett Kontaveit with a battling performance to dramatically extend her Grand Slam singles career.

The 40-year-old tennis legend, who has indicated her intention to retire after the tournament, drew on all her reserves of resilience and sheer fighting spirit to defeat Kontaveit 7-6 (7/4), 2-6, 6-2 at an electrifying Arthur Ashe Stadium.

After leveling the match at 1-1 with a dominant second set performance, Kontaveit appeared to have gained the upper hand over the 23-time Grand Slam singles champion.

But Williams displayed champion mentality in the decider, breaking Kontaveit twice before closing out victory in front of a sell-out crowd featuring the likes of golf superstar Tiger Woods on its feet.

“You know this is what I do best,” a delighted Williams said after her win.

“I love a challenge and love rising to the challenge. I haven’t played many matches but I’ve been practicing really well and my last few matches it just wasn’t coming together…But the last couple of matches here in New York it’s really come together.”

Williams admitted she feared the worst after being unable to respond as Kontaveit improved her game to win the second set.

“I thought ‘Oh my goodness, I’ve got to give my best effort because this could be it,” Williams said. “I just wanted to keep trying and see what I could do and do my best.”

Williams, who won the first of her Grand Slam singles titles as a 17-year-old at the US Open in 1999, said she was now playing with no pressure with the finish line of her remarkable career in sight.

“I don’t have anything to prove, I don’t have anything to win. I have absolutely nothing to lose,” she said.

Williams will return to Arthur Ashe Stadium on Thursday to compete in the women’s doubles, where she will play alongside her elder sister Venus for the first time since 2018.

Meanwhile, Kontaveit admitted to being shaken by a ferociously partisan New York crowd.

“I expected it but it was really hard,” Kontaveit said. “I knew it was coming. It was something I’d never experienced before.”

On day three of the tournament, Serena’s victory once again stole the show.

In other women’s draw action on Wednesday, China’s Wang Xiyu defeated Greece’s third seed Maria Sakkari 3-6, 7-5, 7-5.

The 21-year-old had never advanced past the second round of a Grand Slam tournament before, but she won with 35 winners and 12 break points saved.

Wang, who is ranked 75th in the world, has fond memories of New York after winning the junior US Open there in 2018.

In other action, Tunisia’s beaten Wimbledon finalist Ons Jabeur advanced to the round of 16 with a 7-5, 6-2 victory over American Elizabeth Mandlik.

Coco Gauff of the United States, meanwhile, advanced to the third round with a 6-2, 7-6 (7/4) victory over unseeded Romanian Elena Gabriela Ruse.

That victory sets up an all-American showdown between Gauff and 20th seed Madison Keys, who defeated Italy’s Camila Giorgi in three sets, 6-4, 5-7, 7-6 (10/6).

Leylah Fernandez, the 2021 runner-up, was defeated 6-3, 7-6 (7/3) by Liudmila Samsonova.