Novak Djokovic and Roger Federer were headlining the final 'Manic Monday' at Wimbledon as Ons Jabeur made history by becoming the first Tunisian player to reach the quarter-finals at the All England Club.
World number one Djokovic, chasing a sixth Wimbledon and record-equalling 20th major, is already halfway to becoming just the third man to complete a calendar Grand Slam.
"I look to peak at the biggest tournaments in our sport. At this stage of my career, Grand Slams are the ones that matter the most," said Djokovic who can reach the quarter-finals of a Slam for the 50th time.
The Serb faces Chilean 17th seed Cristian Garin who had never previously won a main draw match at the tournament before this year.
Eight-time champion Federer, who takes on Italy's Lorenzo Sonego, can become the oldest quarter-finalist at Wimbledon in the Open era.
Federer, just five weeks shy of his 40th birthday, is in the Wimbledon last 16 for the 18th time.
In all, it will be his 69th appearance in the fourth round of a Slam but he was quick to salute Djokovic's achievements.
"It's just very, very impressive to see what he's doing this year," said Federer whose third round win over Cameron Norrie gave him the 1,250th victory of his career.
'Manic Monday', when the entire men's and women's fourth round is played out, will not exist from next year as Wimbledon will stage matches on the middle Sunday.
There will be an earlier tweak in the schedule this week with the All England Club announcing that they will move to full capacity crowds from Tuesday's quarter-finals onwards.
Jabeur, the world number 24, defeated Poland's 2020 French Open champion Iga Swiatek 5-7, 6-1, 6-1 to reach her second Slam quarter-final.
The 26-year-old is the first Tunisian woman to reach the last eight at Wimbledon and the first Arab player since Egypt's Ismael El Shafei made the men's quarter-finals in 1974.
"It was a great match. I lost at the end of the first set. I didn't think getting angry would not have helped me," said Jabeur.
Jabeur, a 2020 Australian Open quarter-finalist, will next face Belarus second seed Aryna Sabalenka who defeated Elena Rybakina of Kazakhstan 6-3, 4-6, 6-3.
Sabalenka will be playing in her first Grand Slam quarter-final. Both Jabeur and Sabalenka have a season-leading 33 wins in 2021.
Men's seventh seed Matteo Berrettini became only the fifth Italian man to make the last eight with a quickfire 6-4, 6-3, 6-1 win over Ilya Ivashka of Belarus.
The Queen's Club champion, the first Italian man in the quarter-finals since 1998, will face either Felix Auger-Aliassime of Canada or German fourth seed Alexander Zverev for a semi-final spot.
Meanwhile, second seed Daniil Medvedev, who staged a comeback from two sets down for the first time in his career to beat 2017 runner-up Marin Cilic, faces Hubert Hurkacz.
Polish 14th seed Hurkacz is the only player in the fourth round not to have dropped serve.
Sebastian Korda, whose father Petr made the quarter-finals in 1998, celebrates his 21st birthday on Monday.
He can reach the quarter-finals of a Slam for the first time by beating Russian 25th seed Karen Khachanov.
- Barty eyes last-eight -
Denis Shapovalov, the Canadian 10th seed who put out two-time winner Andy Murray in the last round, faces Spain's Roberto Bautista Agut, a semi-finalist in 2019.
Women's world number one Ashleigh Barty, trying to win the title 50 years on from fellow indigenous Australian Evonne Goolagong Cawley's maiden crown, tackles French Open winner Barbora Krejcikova.
The only British player left in the singles draw is 18-year-old Emma Raducanu who has defied her ranking of 338 to make the second week where she meets Australia's Ajla Tomljanovic.
Raducanu has only just completed her final school exams and has attracted a host of new fans, including rock star Liam Gallagher, the former frontman of Oasis.
"BIBLICAL," Gallagher tweeted in response to Raducanu's third round win over Sorana Cirstea.
Germany's Angelique Kerber, the only former champion left in the women's event, takes on Coco Gauff.
Gauff, 17, is bidding to become the youngest woman to reach a Wimbledon quarter-final since Maria Sharapova in 2004.
Former world number one Karolina Pliskova, the eighth-seeded Czech has also fired 22 aces and faces unseeded Russian Liudmila Samsonova.
Samsonova, ranked 65, has made the most of her wild card to register her best ever performance at a Slam.
Having won the Berlin grass court tournament as a qualifier in the run-up to Wimbledon, the 22-year-old is on a 10-match win streak.
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