The second set was a different story to the first as Anett Kontaveit settled and Serena Williams started to make more unforced errors.
The capacity crowd at Arthur Ashe Stadium, hearing a lost set by Williams, fell silent.
Kontaveit found her groove early and often, breaking Williams with ease in the first game and smashing winners all over the court.
Williams, trying to get up, shouted “Come on!” in Game 3 after hitting some winners of his own. But Kontaveit held firm to take a 30 lead and, crucially, rolled from there.
Williams is almost 41 years old and has battled a number of injuries in recent years. His game is not as consistent as it was five years ago. Still, throughout the set, he showed flashes of his familiar brilliance, chasing down shots and hitting crosscourt winners.
Williams’ serve was her biggest weapon as she hit 10 aces. But he also betrayed her at key moments, like when he doublefaulted on game point to go 41 down.
Williams took a short break after the set, going to the locker room for a few minutes before returning to the court.