Keys, the No. 19 seed and a two-time semifinalist at Melbourne Park, had won the first set. But Rybakina, who like Keys is a precise winner machine when she is playing the tennis she wants to play, had taken the second by seizing the initiative and playing on her front foot. Halfway to the finish, Keys had become a passive counterpuncher.

Hope for an All-American semifinal remains, but will require an Emma Navarro upset of five-time Grand Slam winner Iga Swiatek.

Madison Keys is back into the Australian Open semifinals for a third time after her 3-6, 6-3, 6-4 win over Elina Svitolina of Ukraine.