Novak Djokovic faces a stiff challenge in his quest for a record-breaking 25th Grand Slam on Monday as Elina Svitolina broke down in tears on court at Wimbledon following a deadly barrage of Russian strikes on her native Ukraine.

Seven-time champion Djokovic comes up against Danish 15th seed Holger Rune, who has beaten him twice.

Djokovic, seeking to equal Roger Federer's record of eight Wimbledon men's titles, had surgery last month to repair a torn medial meniscus suffered during the French Open.

The 37-year-old, aiming to pull clear of Margaret Court's mark of 24 majors, has dropped a couple of sets but has largely looked untroubled so far.

Rune, by contrast, was forced to dig deep in his third-round match against Quentin Halys after trailing by two sets to love.

"He looks to me a player that is ready for big things. He's a spectacular player, no doubt," said Djokovic. "He's a very tricky opponent.

"When it comes to competing, obviously we both have that fire. I'm sure on Monday we'll see a lot of fireworks on the court."

Svitolina broke down in tears after reaching the quarter-finals for a third time with a 6-2, 6-1 win against China's Wang Xinyu in just 55 minutes.

The 21st seed, wearing a black ribbon on her white shirt, was in action just hours after Russia struck cities across Ukraine in a missile attack that killed 31 people and heavily damaged a Kyiv children's hospital.

"It's a very difficult day today for all Ukraine people," said the 29-year-old Svitolina, who wept as she conducted a TV interview after her victory.

As she attempted to compose herself, she received a lengthy round of applause from spectators on Court Two.

"It was not easy to focus on the match. Since this morning it has been very difficult to read the news and go on court."

Svitolina will next play Russian-born Kazakh Elena Rybakina, who defeated an injury-hit Anna Kalinskaya 6-3, 3-0.

Rybakina, the 2022 Wimbledon champion, said she did not feel pressure even though she is the highest-ranking player left in the women's draw.

"Every opponent is difficult and I know that I must always bring my best and that's what I try to do every match," she said.

"I'm just really enjoying every time I step out on the court and I am happy I am going fine in the draw and hopefully I can go to the end."

Australian ninth seed Alex de Minaur, who won the 's-Hertogenbosch grass-court tournament last month, prevailed in four sets against France's Arthur Fils to set up a quarter-final against Djokovic or Rune.

Italian 25th seed Lorenzo Musetti tamed big-serving Frenchman Giovanni Mpetshi Perricard, coming from a set down to win 4-6, 6-3, 6-3, 6-2.

Lucky loser Mpetshi Perricard, celebrating his 21st birthday, had been broken just once in three rounds at Wimbledon but Queen's finalist Musetti found the key on Court No. 2, breaking five times as his opponent racked up 42 unforced errors.

"It's tough for me to get emotional but I think today I will," said the Italian. "I've been dreaming of this moment since I was a kid."

Alexander Zverev, the fourth seed, is desperate to shake off his nearly-man tag and win a first Grand Slam.

The German reached the final at Roland Garros last month -- his second Grand Slam final -- though his record at Wimbledon is modest, with the fourth round being his best showing to date.

Standing in his way is American 13th seed Taylor Fritz, who arrived at the All England Club on a high after winning the Eastbourne International on grass.

After ousting world number one Iga Swiatek in the third round, diminutive giant-killer Yulia Putintseva faces Jelena Ostapenko for a place in the last eight.

The world number 35 fought back to end the Polish star's 21-match winning streak on Saturday.

Ostapenko won the French Open in 2017 and reached the Wimbledon semi-finals a year later, but has struggled to hit those heights since then.