Jannik Sinner made a strong statement at the Australian Open by advancing to the quarter-finals on Monday, but fellow champion Madison Keys was eliminated as Melbourne prepared for forecasted temperatures of 45°C.

Fifth seed Lorenzo Musetti fought through challenging conditions to secure a spot in the last eight, where he will face Novak Djokovic. Meanwhile, six-time major champion Iga Swiatek continued her dominant performance in the tournament.

Two-time defending champion Sinner delivered an impressive 6-1, 6-3, 7-6 (7/2) victory over his Italian compatriot and close friend Luciano Darderi. The second seed is now set to face the United States’ eighth seed Ben Shelton, who defeated Norway’s 12th-seeded Casper Ruud in four sets.

Djokovic and Sinner are on track for a high-stakes showdown in the semifinals. Sinner, playing at Margaret Court Arena where temperatures were around 30°C in the early evening, said, “It was difficult to put the match away, but I’m happy I closed it in three sets.”

Sinner served 19 aces during the match and expressed satisfaction with his progress this season. “There’s still room to improve, but I’m happy with how I’ve come back in the new season,” he added.

In another match between friends, Jessica Pegula defeated reigning champion Keys with a score of 6-3, 6-4. The Americans co-host a tennis podcast called “The Player’s Box” and had even planned to record an episode before their match. That plan was abandoned as Pegula dominated the encounter, setting up a last-eight clash with another American, fourth seed Amanda Anisimova.

Anisimova, who reached the finals of the US Open and Wimbledon last year, cooled herself off with ice bags before defeating China’s Wang Xinyu 7-6 (7/4), 6-4. Pegula, the sixth seed, is aiming for her first Grand Slam title at age 31, having previously reached the US Open final in 2024.

Keys made 27 unforced errors compared to Pegula’s 17 and hit six double faults, which contributed to her defeat. As part of a lighthearted bet, Keys will have to eat a slice of apple pie topped with melted cheddar cheese. “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,” she said, expressing pride despite her loss.

Elena Rybakina easily defeated Belgium’s Elise Mertens 6-1, 6-3 and will face second seed Iga Swiatek. The Polish player showcased her dominance by defeating home qualifier Maddison Inglis 6-0, 6-3, moving closer to her first Australian Open title. Swiatek has won all three other majors but is yet to claim the Australian crown.

Inglis, ranked 168th, faced a life-changing opportunity after two-time Melbourne champion Naomi Osaka withdrew injured from their third-round match. Reaching the fourth round earned Inglis a life-changing prize of Aus$480,000 (US$330,000), which she plans to use to buy a toaster and a kettle.

• Melbourne sizzles –

After brutal weather forced the suspension of matches on Saturday, temperatures rose sharply again on Monday. Longer matches included 10-minute breaks in certain situations to protect players’ health. Temperatures are expected to reach a scorching 45°C on Tuesday, prompting the possibility of matches being played under roofs on the three courts that have them.

In the final match of the day on Rod Laver Arena, Shelton defeated father-to-be Ruud with a score of 3-6, 6-4, 6-3, 6-4, celebrating his victory with a loud roar.

Djokovic was originally scheduled to face Czech player Jakub Mensik in the night match, but the 20-year-old pulled out injured on Sunday. This allowed the 38-year-old Serb to advance to the last eight without playing a single point. Djokovic will now face Musetti, who defeated American ninth seed Taylor Fritz 6-2, 7-5, 6-4.

Despite Djokovic winning nine of their previous 10 meetings, Musetti expressed confidence. “I feel ready to try to push him to his maximum,” he said.