Defending champion Carlos Alcaraz is up against 16th seed Ugo Humbert, while top seed Jannik Sinner faces 14th seed Ben Shelton.
U.S. Open champion Coco Gauff will take on compatriot Emma Navarro, seeded 19, while French Open finalist Jasmine Paolini seeks to keep her career-best Wimbledon campaign going with a win over 12th seed Madison Keys.
Here are the latest results and highlights
TOP MEN'S MATCH: ALCARAZ V HUMBERT
Spanish third seed Alcaraz was on the brink of defeat against Frances Tiafoe but fought back to edge the fourth set in a tiebreak before claiming a convincing victory in the fifth.
The French Open champion said he made some mistakes with his serve during the match, but his fortitude during the fifth set got him the win.
Frenchman Humbert prevailed over Brandon Nakashima over four closely fought sets.
Alcaraz and Humbert are locked at 1-1 in head-to-head meetings.
TOP WOMEN'S MATCH: GAUFF V NAVARRO
Second seed Gauff has reached the Wimbledon fourth round twice, but has never gone further, with Wimbledon remaining the toughest Grand Slam to crack for the 20-year-old who has won the U.S. Open, reached the French Open final and the Australian Open semis.
Coming off three straight-set wins, Gauff is looking well poised to break through that barrier this year.
"I think this year I'm just playing with a lot more confidence, trusting my ground game a lot and returning a whole lot better," she said on Friday.
However, Gauff's opponent Navarro is in her best form on grass, reaching Wimbledon's fourth round for the first time.
"I know I have the level inside of me that can beat a player like (Gauff)," Navarro said. "It's maybe just a matter of doing it on a bigger stage."
SINNER FACES SURVIVOR SHELTON
Top seed Sinner faced some adversity in the first two rounds where he dropped a set each, then sailed through the third round with a straight-sets win over Miomir Kecmanovic.
Shelton has been dragged into a fifth set in each round, and draws confidence from his ability to prevail under pressure.
"I definitely feel confident in how fit I am right now, how prepared I am to go the distance. I know I'm going to fight until the end out there," Shelton said.
"I think it's a great opportunity for me, a great challenge and test. The biggest challenge in tennis playing the top-ranked player in the world."
PAOLINI LOOKS FOR KEYS TO VICTORY
Seventh seed Paolini is yet to drop a set as she tries to make it to the Wimbledon quarter-finals for the first time, and she is well aware of the threat posed by her next opponent Keys.
"She's an aggressive player, for sure. She serves very fast. I think she's one of the best hitters in the tour because I love how she plays," Paolini said on Friday.
WRIST WORRY FOR RESURGENT RADUCANU
Local hope Emma Raducanu is on a high after knocking out ninth seed Maria Sakkari, but the 2021 U.S. Open champion pulled out of the mixed doubles with Andy Murray due to a wrist issue.
Wildcard Raducanu is set to face qualifier Lulu Sun as they both seek to reach the Wimbledon quarter-finals for the first time.
WIMBLEDON ORDER OF PLAY ON SUNDAY
Here is the order of play on the main showcourts on the seventh day of Wimbledon (prefix number denotes seeding):
CENTRE COURT (1230 GMT)
Carlos Alcaraz (Spain) v Ugo Humbert (France)
Lulu Sun (New Zealand) v Emma Raducanu (Britain)
Emma Navarro (U.S.) v 2-Coco Gauff (U.S.)Emma Navarro (U.S.) v Coco Gauff (U.S.)
COURT ONE (1200 GMT)
Jasmine Paolini (Italy) v Madison Keys (U.S.)