Serena Williams was upset Victoria Azarenka in the US Open semifinals.
CNN reports that Williams is on a quest to win a record 24th Grand Slam title.
Azarenka rallied for a 1-6 6-3 6-3 victory on Thursday night in New York.
It's the first time Azarenka beat Williams in a major in 11 attempts.
Williams took a mid-game medical timeout for an Achilles tendon issue in the second game of the thirds set.