Jessica Pegula of the US celebrates as she defeats Romania's Irina-Camelia Begu during their fourth round match of the French Open tennis tournament at the Roland Garros stadium, May 30, 2022 in Paris. (MICHEL EULER / AP)

PARIS - American Jessica Pegula fought back to defeat 63rd-ranked Romanian Irina-Camelia Begu 4-6 6-2 6-3 on Monday to reach the quarter-finals of the French Open for the first time.

The 11th-seeded Pegula, the highest seed remaining in the women's draw after world number one Iga Swiatek, became the third American woman to reach the last eight of the claycourt Grand Slam at this year's Roland Garros tournament.

Pegula, who made the quarter-finals of the Australian Open in 2021 and 2022, did not lose a set in her first three rounds but Begu broke the American early and then sealed the opening set with a second break

Pegula, who made the quarter-finals of the Australian Open in 2021 and 2022, did not lose a set in her first three rounds but Begu broke the American early and then sealed the opening set with a second break.

Pegula had lost both of their previous meetings in straight sets coming into Monday's contest and was forced to dig deep.

The 28-year-old found her rhythm and broke Begu's serve three times over the next two sets to book her spot against Swiatek.

"It's been weird because the first few matches until today I was cruising really fast, getting really big leads really quickly, losing some of those leads," Pegula said.

"Today I definitely didn't feel like I was playing my best from the get go, getting a little frustrated and then had to claw my way back. So it was basically the opposite of what I've been doing.

"I just tried to stay calm and think about what I had to do and also just try to hold on to my serve and get as many chances and just kind of grind it out.

"I was able to not get frustrated and then stay calm and figure out strategically what I needed to do. And then I was able to execute that, luckily."

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Jessica Pegula of the US returns the ball to Romania's Irina-Camelia Begu during their fourth round match of the French Open tennis tournament at the Roland Garros stadium, May 30, 2022 in Paris. (MICHEL EULER / AP)

With her victory against the 31-year-old Begu, Pegula also ensured she will break into top 10 of the women's rankings from her current career-high position of 11th when they are updated next Monday after the tournament.

"It feels weird ... I feel like I haven't really been able to like appreciate it because I still am like in a big tournament right now," Pegula told reporters. "It's just been amazing.

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"I knew it was going to be really tough because obviously the higher you get, the harder it is to move up as well ... so I thought it was going to be a very tough goal to reach.

"But I'm pretty happy that halfway through and I have been able to reach that. It was definitely on my goals, but I don't think I was putting a ton of pressure on it."