Novak Djokovic advanced to the quarterfinals of the Australian Open after his scheduled opponent Jakub Mensik withdrew due to an abdominal injury.

Sixteenth-seeded Mensik recorded a 6-2, 7-6 (5), 7-6 (5) victory over Ethan Quinn on Saturday to set up the Czech’s encounter with the 24-time major champion on Monday. Alas, Mensik took to social media on Sunday to announce that he was bowing out of the match.

“This is a tough one to write,” Mensik, 20, wrote on Instagram. “After doing everything we could to keep going, I have to withdraw from the Australian Open due to an abdominal muscle injury that has progressed over the last matches.

“After a long discussions with my team and doctors we decided not to step on court (on Monday).

“Even though I’m disappointed, making the fourth round here for the first time is something I will carry with me for a long time. I felt so much energy from the fans and the atmosphere in Melbourne was truly special. Now it’s time to recover properly.”

Djokovic, 38, will face fifth-seeded Lorenzo Musetti, who defeated ninth-seeded Taylor Fritz 6-2, 7-5, 6-4 to reach his fourth major quarterfinal and first at the Australian Open.

Musetti had the edge in winners, 33-23, and was on the favorable side with 24 unforced errors, to 34 for Fritz. The Italian won 4 of 9 break-point opportunities, to 0-for-2 for his American opponent.

Ranked a career-best No. 5 in the world, Musetti also had the edge by winning 84% (46 of 55) of his first-serve points, to 64% for Fritz (32 of 50).

“I think today (my serve) was really working well,” said Musetti, 23, who struck 13 aces. “I think I made one of my best performances in aces in my career so far, so I’m really, really happy.”

Djokovic is 9-1, including six consecutive wins, against Musetti in their ATP head-to-head matchups. Musetti improved to 4-3 against Fritz, a 28-year-old who beat him in November in Turin and is ranked No. 9 in the world.

–Field Level Media