Jessica Pegula wins and plays against Aryna Sabalenka for the title

As her chances of reaching the US Open final faded, Jessica Pegula muttered to herself about how poorly she was playing.

The only good news was that things couldn't get any worse.

The 30-year-old American faced a quick and embarrassing loss in the biggest match of her career, but found her game just in time to eventually overwhelm Karolina Muchova 1-6, 6-4, 6-2.

The win gives Pegula, seeded No. 6, the opportunity to play No. 2 seed Aryna Sabalenka for her first Grand Slam title on Saturday.

“I came out completely floored. She made me look like a rookie,” Pegula said on ESPN. “I was about to burst into tears. She wore me out and I was able to find a way, find some adrenaline, find my legs and then I started playing the way I wanted to play. It took a while, but I honestly don't know how I changed that.”