Jessica Pegula will take on Amanda Anisimova in an intriguing quarter-final after ending Madison Keys' Australian Open title defence.

Keys stormed to an unexpected success in Melbourne last year, but there will be no repeat in 2026 after she lost 6-3 6-4 to her fellow American.

Pegula required just 78 minutes to get the job done on Monday, setting up another all-American tie in the quarter-finals, against the finalist of the last two majors, Anisimova.

Keys and Pegula are close friends off the court, and the latter quipped that she has now won a bet involving apple pie and cheddar cheese.

"We have Thanksgiving and I don't know why, my grandparents are Canadian, but we have this tradition my mum always did," said Pegula.

"Tell me if this is weird or if it's real. They would melt cheddar cheese on their apple pie."

In her post-match press conference, Keys said: "A bet is a bet, so I'll do it. I hope it's less gross than I think it's going to be but we'll find out [when I eat it], I guess."

On her title defence, Keys added: "Coming back and being defending champion, and dealing with all of the extra pressure and nerves – I am really proud of myself for the way I handled it."

4 - 4+ Americans have made the QFs in Women’s Singles at the Australian Open for the first time since 2001 (Serena Williams, Venus Williams, Jennifer Capriati, Monica Seles and Lindsay Davenport). Quartet.#AusOpen | @AustralianOpen @WTA @AnisimovaAmanda @JPegula @CocoGauff pic.twitter.com/HX7nBryB9o

— OptaAce (@OptaAce) January 26, 2026

Anisimova continued her fine form with a 7-6 (7-4) 6-4 victory over Xinyu Wang.

She is the second-youngest woman to make the quarter-finals at all four majors this decade, older only than Iga Swiatek.

Data Debrief: Miss Americana

At the age of 31 years and 328 days, Pegula is the oldest American woman in the Open Era to defeat a defending champion at a major, surpassing Serena Williams (31 years, 243 days at Roland-Garros in 2013).

Pegula is also the oldest player to reach consecutive major quarter-finals without dropping a set since Williams at the Australian Open in 2017.

At least four American women have now made the quarters at the Australian Open for the first time since 2001 (Williams, Venus Williams, Jennifer Capriati, Monica Seles and Lindsay Davenport).