Serena Williams has been knocked out of the US Open. Photo / Getty
Serena Williams' quest for a record 24th Grand Slam title has fallen short once again.
The former world number one has been upset in the US Open semifinals by Belarusian Victoria Azarenka - extending her Grand Slam win drought to nine.
Williams has long been level on Margaret Court's record for major titles, but yet to break it, with her last major title came in the 2017 Australian Open.
The 38-year-old took a commanding advantage with a 6-1 first set win, but dropped the next two 3-6, 1-6. Azarenka's comeback is made all the more impressive, having not made a Grand Slam semifinal since the 2013 US Open.
Williams put herself in a comfortable position after rolling through the first set. But Azarenka, a former world number one herself, won five straight games to close out the second and surge to a 3-0 lead in the third.
Up 5-3 in the final set needing two points for victory, Azarenka's win was confirmed thanks to two sublime serves, the second being an ace which Williams challenged unsuccessfully. Azarenka claimed her first win over the American in their 11 Grand Slam meetings.
Azarenka will now face 2018 US Open champion Naomi Osaka in the decider. They were supposed to meet in the final of the Western & Southern Open, played this year in Flushing Meadows immediately before the U.S. Open, but Osaka withdraw because of a hamstring injury.
Azarenka has won 11 matches in a row; Osaka's streak is at 10 after her 7-6 (1), 3-6, 6-3 win over Jennifer Brady in a hard-hitting semifinal filled with fast serves and strong forehands.
"It means a lot for me. I kind of consider New York my second home," said Osaka, who was born in Japan and moved to the United States as a child. "I love the atmosphere, even though there's no people here. I feel like this court kind of suits me well."
It suited both players just fine.
Osaka served at up to 120 mph; Brady reached 117 mph. And they pounded the ball once it was in play, too, particularly off the forehand side.
"I just felt like I was sticking it out. It felt like we were trading serves," Osaka said. "I tried to adjust a little bit on her serve in the third set so maybe that helped."
They combined for 70 winners — 35 apiece — to just 42 unforced errors, each as good as the other, and it took a bit of luck to swing things after one hour, 45 minutes. That's when, at 2-1 in the third set, Osaka earned her first break point with a backhand that clipped the net tape and trickled over. She was able to convert the chance when she hit a deep return of a 110 mph serve, and Brady's backhand in response was called long — although a television replay showed it actually caught a piece of the back of the baseline.
Brady did not challenge the ruling.
Ashe is one of only two courts at the U.S. Open using line judges this year; to reduce the number of people on site, the tournament used electronic line-calling in the other arenas.