Serena Williams’ hope of a record equalling 24th Grand Slam has been dashed after being knocked out at the US Open semifinal by Victoria Azarenka.

The American had needed treatment on her foot while trailing 1-0 40-40 in the third set.

“I started really strong,” said Williams. “Then she just kept fighting. She just changed and started playing better and better. Maybe I took a little too much off the gas pedal at some point. She played really well.

“It’s obviously disappointing. At the same time, I did what I could today. I feel like other times I’ve been close and I could have done better. Today I felt like I gave a lot.”

The 38-year-old who looked supreme in three first set, was defeated 1-6 6-3 6-3 and will not have a final rematch with Naomi Osaka who had earlier beaten Jennifer Brady.

Instead, it is two-time Australian Open champion Azarenka who will face Osaka after coming from behind to stun Williams out of her homeland event.

“I knew it wasn’t over at 5-3,” said the Belarusian. “I’ve been there before. Today was going to be different. I was young, my ego was way too big. Now it’s a little smaller and the result’s coming.”

The 31-year-old has been in poor form since 2013.

“I needed to find energy to climb out of the hole and it wasn’t easy,” said Azarenka, who has said she contemplated retirement at times in recent years. “Hopefully it inspires women to go after their dreams, they can do anything.”

Azarenka had been in custody battle with her former partner over their three-year-old son, Leo which kept her away for several spells and took its toll on and off court, while her confidence ebbed away.