Jessica Pegula is looking for "revenge" against Aryna Sabalenka in the US Open final after losing out on the title to her in Cincinnati.

Pegula will play in her first-ever grand slam final this weekend, becoming the oldest American to do so in the Open Era at 30 years and 193 days.

She had to do it the hard way though, coming from behind to beat Karolina Muchova 1-6 6-4 6-2 in a semi-final that lasted over two hours.

Pegula lost in straight sets when she faced Sabalenka in the Cincinnati Open final, but she is hopeful she can flip the script this time around.

"Playing Aryna is going to be really tough," Pegula said. 

"She showed how tough she is [in the first semi] and why she's probably the favourite to win this tournament.

"It'll be a rematch of Cincinnati, so hopefully I can get some revenge out here.

"It's kind of crazy that we're playing each other again in the finals, but I think it just shows how much great hard-court tennis we've been playing. She's going to be tough to beat, but that's what the finals are for, so I'm ready."

Sabalenka overcame another American in her semi-final, beating Emma Navarro 6-3 7-6 (7-2).

She has reached a second consecutive US Open final, having missed out on the title to Coco Gauff last year, and has reached each of the last four grand slam finals on hard courts, winning both of those in Australia. 

Having already beaten one of the home favourites, Sabalenka will be expecting another raucous atmosphere when she faces Pegula.

"Well now you're cheering for me, it's a bit too late," a Sabalenka joked after the match. 

"It really means a lot and even though you guys were supporting her, I still had goosebumps for you cheering."