Serena Williams showed she has no intention of ending her singles career without a fight after beating second seed Anett Kontaveit on another remarkable night at the US Open.
Serena Williams shocked the US Open’s second seed in New York, despite currently being ranked 605th.
Her opponent Anett Kontaveit is ranked second in the world but has struggled to live up to her status in recent months.
The American recently announced her intention to retire after her home major, though giving no specific timeline, and she is now into the third round. Her next match will be against Australia's Ajla Tomljanovic on Friday.
"I'm a pretty good player, this is what I do best. I love a challenge and I'm rising to the challenge," said the six-time US Open champion, who first won at Flushing Meadows in 1999.
"I haven't played many matches but I've been practising really well. Now it's coming together in New York."
23-time major singles champion Williams edged a tense opening set and suffered a dip of energy from the start of the second set as Kontaveit levelled but she recovered to win an edgy decider.
"I'm just pleased I showed up because the last few tournaments I didn't show up," said Williams.
The world number two fought off three break points to hold for 4-3 after a game that lasted more than 11 minutes and faced another in her next service game.
Williams had only played four times since making her return from an 11-month injury lay-off, with her most recent match ending in a thrashing by British number one Emma Raducanu in Cincinnati.