Sept. 11 (UPI) -- Serena Williams roared in the first set of her U.S. Open semifinal clash with Victoria Azarenka before her unseeded foe climbed back into the match for an upset of the 23-time Grand Slam champion in Queens, N.Y.
Azarenka's 1-6, 6-3, 6-3 win Thursday at Arthur Ashe Stadium ended Williams' quest for a record-tying 24th major singles title and a spot in the 2020 U.S. Open singles final.
"I dug myself in a big hole -- she dug me in a big hole in the first set," Azarenka told reporters. "I had to climb my way out of there, one by one. I'm very happy that I was able to turn it around."
The Belarusian will face 2018 champion Naomi Osaka in the women's final Saturday at the USTA Billie Jean King National Tennis Center. Azarenka -- a former world No. 1 -- is a two-time Grand Slam winner. Osaka also will vie for her third major title Saturday in Queens.
Azarenka is 5-19 in career matches against Williams. Thursday's triumph marked her first win over Williams in a Grand Slam. Williams said an achilles injury, which she sustained during the match, contributed to the setback.
Williams jumped out to a 4-0 lead in the first set before Azarenka won her first game. Williams then closed out the set with back-to-back game wins.
The third-seeded American also won the first game of the second set before Azarenka bounced back to win the fourth, fifth and sixth game. Williams won the next game, but Azarenka closed out the set to tie the match.
Azarenka carried that momentum into the third set and put Williams on the ropes with a 3-0 lead. Williams and Azarenka exchanged points for the next five games before Azarenka ripped an ace for match point to end the one-hour, 55-minute affair.
"I started really strong," Williams said. "Then she kept fighting. She changed and played better and better. Maybe I took too much off the gas pedal. She played really well."
Williams had eight aces, three double faults, 35 winners and 28 unforced errors. Azarenka had two aces, five double faults, 24 winners and 17 errors.
Osaka advanced Thursday with a three-set win over American Jennifer Brady. The No. 4 seed beat the No. 28 seed 7-6, 3-6, 6-3 in two hours and eight minutes.
Williams said she plans to compete in the French Open, set for Sept. 11 through Oct. 1 in Paris, where she will resume her quest to tie Margaret Court's record of 24 Grand Slam triumphs.