American teenager Coco Gauff stormed into the US Open semi-finals for the first time with a superb, dominant victory over Latvia's Jelena Ostapenko.

The American dropped only five points in a 20-minute first-set demolition and then claimed a closer second set.

She will play 10th seed Karolina Muchova of the Czech Republic or Romania's Sorana Cirstea, the 30th seed, in the semi-finals on Thursday.

"It feels great, I'm so happy," said Gauff. "I lost in the quarter-finals stage last year and wanted to do better this year. I have a long way to go but I'm happy and will get ready for the next one.

"I didn't feel comfortable at all the whole match, even at match point. She has the ability to come back no matter the scoreline so I was just trying to play every ball and hit it deep. I was trying my best to be aggressive when I could.

"She has had a great tournament and I speak and get along with her well off the court.

"The defence has always been there, but I've been improving my offence and that's showing on the court.

"I played well. This is my shortest match of the tournament by far so maybe I will get back and hit the [practice] courts."

Gauff, aiming to win her first Grand Slam title after losing to Iga Swiatek in the 2022 French Open final, had seen three of her first four matches at this year's US Open go to a deciding set.

But after only nine minutes of action in Tuesday's opening match on Arthur Ashe Stadium, Gauff had raced into a 3-0 lead with a double break of serve, as Ostapenko, who knocked out world number one Swiatek in the last 16, made 10 unforced errors.

Gauff did not lose a point on her second serve in the opening set and then broke the 20th seed's serve in the first game of the second set.

Ostapenko did immediately break back for her first game of the match, only for Gauff to regain control a few minutes later.