American teenager Coco Gauff reached her first US Open singles final after beating Karolina Muchova in a semi-final disrupted by protesters.

Gauff could not convert a match point when serving at 5-4, but broke Muchova to seal victory after winning a 40-shot rally to create the sixth opportunity.

The sixth seed plays Aryna Sabalenka or Madison Keys in Saturday's final.

It will be her second attempt to win a Grand Slam singles final after finishing runner-up to Poland's Iga Swiatek at the 2022 French Open.

Gauff raised her fist after clinching the win, signalling her defiance and fight, as the home crowd erupted on an exultant Arthur Ashe Stadium.

After letting out another roar of celebration, she made a heart sign to the fans as a thank you for helping her get over the line.

Ultimately, the way Gauff finally secured victory was testament to her own resolve and a mental fortitude which she says has developed over a successful North American hard-court season.

"Some of those points it was so loud, I don't know if my ears will be OK. Please be louder - this is crazy," Gauff told the crowd in her on-court interview.

"I grew up watching this tournament, it feels so special. But the job is not done."

Belarusian second seed Sabalenka, who will become the new world number one after the tournament, meets 17th seed Keys in the second semi-final later on Thursday.

More to follow.