Jessica Pegula advanced to her first-ever major semi-final, stunning Iga Swiatek in straight sets at the US Open on Wednesday.

The home favourite became the fourth American to reach the semi-finals of this year's tournament after Emma Navarro, Taylor Fritz and Frances Tiafoe.  

Pegula took advantage of the world number one's off-night, cruising through 6-2 6-4 in just under 90 minutes on Arthur Ashe Stadium.

There was little let-up for Swiatek, who lost her serve twice in quick succession at the start of the match as Pegula raced into a commanding lead, and the sixth seed recovered well after going behind in the second set to pull back in front.

And Pegula, who made just one double fault, and 22 unforced errors compared to Swiatek's 41, believes that was the difference in the quarter-final.

"I thought I played a really clean match, served pretty well, returned well," Pegula said.

"I feel like I didn't really do anything that bad and was able to kind of jump on her really early, and I think frustrate her.

"I was able to keep my level even when she picked it up in the second set."

Pegula will face Karolina Muchova for a place in the final. 

Data Debrief: Righting wrongs

Going into Wednesday's match, history was not exactly on Pegula's side as she held a 0-6 record in her previous grand slam quarter-finals. 

However, a quick start ensured that she claimed her 21st WTA top 10 win of her career - in the past four decades, only two US players have claimed more without reaching a women's singles final at a grand slam, though she will be hoping to avoid staying on that list.

Pegula is also the fourth American in the Open Era to reach the women's singles semi-finals at the Canadian, Cincinnati and US Open in a calendar year after Rosemary Casals (1970), Serena Williams (2013-15) and Sloane Stephens (2017).