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.
Williams, ranked 413th and turning 41 next month, won 7-6 (7-4) 2-6 6-2 to stun the Estonian in New York.
The American recently announced her intention to retire after her home major and is now into the third round.
Williams will play Australia's Ajla Tomljanovic next on Friday.
A few weeks ago, Williams announced she was "evolving away" from playing in an essay for fashion magazine Vogue but agreed after beating Montenegro's Danka Kovinic on Monday she had been vague about her exact timeline.