Jessica Pegula outlasts Elina Svitolina to reach semifinals in Washington, D.C.

WATCH: Jessica Pegula came from behind to beat Elina Svitolina in the quarterfinals of the Mubadala Citi DC Open.

Jessica Pegula will confess that two wins over Elina Svitolina in 2021 were part of what sparked her self-belief that she could rise to the top of the game.

Two years later, with both at very different stages of their careers, the two met again on Friday at the Mubuadala Citi DC Open—where Pegula, now a Top 10 stalwart, outlasted a resurgent Svitolina in three sets.

In the first women's quarterfinal played at the combined 500-level event, the American rallied from losing the first set of the pari's quarterfinal match to win 4-6, 6-3, 6-4 win in two hours and eight minutes, and reach her fifth semifinal of the season.

"I have tons of respect for her; she just had a baby, everything she's going through with her country. I told her that she came back as a new person," Pegula said after the match. You can see the competitiveness in her, and I've always really respected that about her.

"She was one of my first big wins when I broke through a couple of years ago, and to beat someone as tough as her gave me a lot of confidence. I always had a lot of respect for how she competes and her attitude on court."

Pegula hit 27 winners and saved six of the seven break points she faced in the match, which she won on her third match point. After losing her 2-all service game as the only player broken in the opening set, Pegula never lost serve again. She saved five break points in a five-deuce sixth game of the decider, to lead 4-2, and saved another when she served out the match.

The second and third sets proved particularly high-quality; after Pegula and Svitolina each hit just four winners in the first 10 games, they ended the match with 27 and 23 winners, respectively. The Ukrainian, who entered the tournament at No. 27 in the WTA rankings after being unranked in April when she returned to tennis from maternity leave, came within a set of her third Top 10 in the just over three months since then.

"I think we play very similar as well, we're very solid from both sides, so I knew it was going to be a tough match, and that's what it was," Pegula said. "I was like, 'If I don't serve this out,' it might been a quick 5-7, I would've lost. I was so tired. I know that sounds terrible to say ... I sweated through [my] entire [dress]. It was cooler out today, but super humid. It was a physical match."

For a spot in her second final of the season, Pegula will next face either No.4 seed Maria Sakkari or No.7 seed Madison Keys, who'll play on Friday night. Sakkari defeated 2021 US Open finalist Leylah Fernandez 7-5, 6-2 earlier in the day in a second-round match that was held over from Thursday due to rain.