CNN  — 

Go Jessica!

World No. 61 Jessica Pegula stunned No. 5 seed Elina Svitolina at the Australian Open to advance to the quarterfinals on Monday.

The 26-year-old American, who is the daughter of the NFL team Buffalo Bills owners Kim and Terry Pegula, won 6-4, 3-6, 6-3 on Rod Laver Arena to reach the last eight of a grand slam for the first time.

Pegula was the aggressor from the outset, with Svitolina unusually passive, allowing the American to dictate the early proceedings, clinching the first set.

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Pegula celebrates after defeating  Svitolina.

Ukrainian Svitolina rallied in the second set and helped by a patchy spell from Pegula leveled the match. But Pegula recovered her poise and ran away in the final set to reach the last eight of a grand slam for the first time in her career.

“I’m hitting the ball really well, I thought I served really well, which is really important, especially against the top players. Any extra free points you can get is huge,” Pegula said afterwards.

“I’m just happy that I’m competing well, hitting well, moving well. I feel good, everything feels pretty solid, so I’m just going to take that to the next match.”

Pegula’s parents are also the owners of the NHL’s Buffalo Sabres and after her victory, she signed one of the TV cameras – as is tradition –“Hi Mom. Hi Dad. See u next rnd.”

Her victory also delighted the Bills’ Twitter account, with it writing: “LET’S GOOOOO.”

Pegula celebrates after defeating  Svitolina.

In beating Svitolina, the 26-year-old recorded her first career top-10 victory. At this year’s grand slam, Pegula has already beaten two-time Australian Open champion Victoria Azarenka, US Open champion Sam Stosur and Kristina Mladenovic without dropping a set.

For the 26-year-old Svitolina, it was her sixth grand slam loss to a player ranked outside the top 30 since she became a top-10 mainstay herself in May 2017 as she searches for her maiden grand slam title.

“It was not a good day for me today,” Svitolina told the media afterwards. “I was making way too many errors. It is tough to pick why it was like this but a mixture of things.

“It’s disappointing because I’ve been playing very good but I feel like it was one of those days where nothing was going my way.”

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Pegula plays a backhand in her match against Svitolina.

Pegula’s victory sets up a meeting with her compatriot and No. 22 Jennifer Brady, who overcame No. 28 seed Donna Vekic 6-1, 7-5 on Monday.

Brady had her own message for Pegula after the game, signing “Bring it Jess” before departing Rod Laver Arena.