Kenin, the fourth seed, lost in the second round to Kaia Kanepi of Estonia.
MELBOURNE, Australia — Sofia Kenin, the reigning champion, was knocked out of the Australian Open on Thursday in a decisive 3-6, 2-6 loss to the unseeded Kaia Kanepi of Estonia.
Kenin’s second-round defeat was the first major upset of the 2021 Australian Open. She was the No. 4 seed in the tournament and was the WTA Player of the Year in 2020, when she won the Australian Open in February and made the French Open final in October.
Kenin, though, has struggled to find her form this year. She lost in the quarterfinals of the Abu Dhabi Open in January, dropping the third set, 6-0, to Maria Sakkari of Greece, then was eliminated in the tuneup event to this tournament by Jessica Pegula of the United States. Kenin left the court in tears after that loss.
Kenin, 22, was never in Thursday’s match against Kanepi, who is 35 and probably on the back end of her career. Physically imposing at 5-foot-11, Kanepi overpowered Kenin with 10 aces and also prompted her to make too many uncustomary errors. Kanepi closed out the match with two aces.
Kenin was expressionless as she grabbed her bags and hurried off the court.
This is a developing story, which will be updated.