MELBOURNE, Australia -- Danielle Collins is back in the Australian Open quarterfinals after a 4-6, 6-4, 6-4 comeback win over No. 19-seeded Elise Mertens in a match lasting almost three hours Monday in temperatures in the low 90s on Rod Laver Arena.
Collins joins two other Americans in the final eight at Melbourne Park. Jessica Pegula and Madison Keys are the other Americans in the quarterfinals and will play their matches on Tuesday. It is the second year in a row that three Americans have featured in the quarterfinals.
It was the first time Collins has rallied from a set down to win back-to-back matches at a Grand Slam tournament.
The 28-year-old American also dropped the first set in her third-round win over Clara Tauson. Collins has won now seven major matches when losing the first set (two this week) since 2019. That is tied with Kaia Kanepi for most of any woman in that span.
The No. 27 seed was a semifinalist at the 2019 Australian Open, which remains her best run at a major.
A win over French veteran Alize Cornet in the next round would get Collins back into the last four.
"Today it was really physically tough for me," Collins said. "I played a long match the other day -- 2½ hours -- and then I played doubles, so I spent about five hours on court.
"I had to make a lot of technical adjustments to make myself comfortable moving around, especially serving."
Collins was aggressive with her ground strokes, hitting 45 winners and and making 41 errors against Mertens. She converted five of her 18 break-point chances and clinched the victory when Mertens, a semifinalist in Australia in 2018, served a double-fault.
Cornet survived a second-set meltdown to advance to her first Grand Slam quarterfinal after 63 main-draw appearances with a 6-4, 3-6, 6-4 win over Simona Halep.
"It's never too late to try again!'' Cornet said in her on-court TV interview. "To be in my first quarterfinal. It's a dream come true.
"The journey goes on. I still can't believe it."
Cornet led by a set and 3-1 before losing five consecutive games and 16 straight points to send the match to a decider. Halep saved two match points on her serve in the ninth game before Cornet clinched the match in the 10th. She dropped to her knees and clasped her hands together as she looked up to her support team when Halep netted a return.
Cornet had a 3-1 lead in their head-to-head meetings and improved on that record in the Rod Laver Arena fourth-rounder.
Cornet made her Grand Slam singles debut as a wild-card entry at the 2005 French Open. She is the first French woman to reach an Australian Open quarterfinal since Marion Bartoli in 2009. Halep won the French Open in 2018 and Wimbledon in 2019. She lost the 2018 Australian Open final to Caroline Wozniacki.
Cornet used bags of ice to cool down her head during changeovers against Halep, and draped cold towels over her neck.
"I just stopped thinking after ... 30 minutes of playing. My brain was already like, overloaded,'' Cornet said. "My vision was not clear anymore. My hands were shaking.''
But, she added, "I thought, on the other side of the court, she was not feeling much better than me.''
In the last match of Day 8 on the women's side, 115th-ranked Kaia Kanepi upset second-seeded Aryna Sabalenka 5-7, 6-2, 7-6 (7) to advance to the quarterfinals for the first time, finally completing a Grand Slam set after twice making it to the last eight at each of the other three major tournaments.
Information from The Associated Press was used in this report.