The surprise means only two of the top eight seeded women are still in the field after only four days of action at the All England Club. Van Uytvanck entered this year's edition of Wimbledon with a 1-4 record in the grass-court tournament.
Muguruza, meanwhile, not only won her second career Grand Slam title in 2017 at Wimbledon, but also reached the 2015 final. She was the 2016 French Open champion, too.
Unseeded American Taylor Fritz has taken a two-sets-to-one lead over No. 4 Alexander Zverev in Wimbledon's second round in a match suspended by darkness.
Fritz leads 4-6, 7-5, 7-6 (0). He is a 20-year-old ranked 68th who has never been to the third round at a Grand Slam tournament.
They will resume with the start of the fourth set on Friday.
Denis Shapovalov is the latest seeded player to exit the men's draw at Wimbledon after Benoit Paire beat the 19-year-old Canadian 0-6, 6-2, 6-4, 7-6 (3).
Having raced through the first set in just 19 minutes — making only one unforced error — 26th-seeded Shapovalov was unable to maintain his level.
Paire took advantage, with the Frenchman losing just seven of 60 points on his first serve from the end of the first set onward.
Shapovalov is the 14th seed to be knocked out in the men's draw. The 47th-ranked Paire will next face fifth-seeded Juan Martin del Potro after the Argentine defeated Feliciano Lopez 6-4, 6-1, 6-2.
Novak Djokovic says the injury that forced him to call a medical timeout during his third round victory at Wimbledon is "nothing major."
The three-time champion called for the trainer when leading Argentine Horacio Zeballos 6-1, 6-2, 4-3 and received treatment on his left leg.
"I've been doing checkups now," Djokovic said. "It seems like it's nothing major. Tomorrow I'll see on the practice session how it feels. Hopefully it's going to be fine."
The 12th-seeded Djokovic showed no ill-effects as he closed out the match by winning the next two games to win the final set 6-3.
Djokovic — who missed the second half of 2017 and three months this season with a right elbow injury — will next face either 21st-seeded Kyle Edmund or American qualifier Bradley Klahn.
Top-ranked Simona Halep won the last 10 games to beat Saisai Zheng of China 7-5, 6-0 in the second round of Wimbledon.
Saisai led 5-3 in the first set but Halep broke back for 5-5 and cruised the rest of the way against her 126th-ranked opponent.
Halep won her first Grand Slam title at the French Open.
She lost in the quarterfinals at Wimbledon in 2016 and 2017.
Novak Djokovic overcame an apparent thigh problem to beat Horacio Zeballos 6-1, 6-2, 6-3 and reach the third round at Wimbledon.
Djokovic called for a trainer and had his left leg massaged when leading 4-3 in the third set. But he easily held serve in the next game and broke Zeballos again to close out the match.
Top-ranked Rafael Nadal also advanced with a 6-4, 6-3, 6-4 win over Mikhail Kukushkin of Kazakhstan on Centre Court.
Nadal won only 64 percent of points on his first serve and faced 13 break points — including three in the first game of the match — but he saved 11 of them and converted five of his own to wrap up the win in 2 hours, 23 minutes on Centre Court.
The 11-time French Open champion is looking for his third title at the All England Club and first since 2010.
Guido Pella of Argentina came from two sets down to stun third-seeded Marin Cilic at Wimbledon, beating last year's finalist 3-6, 1-6, 6-4, 7-6 (3), 7-5 in the second round.
Cilic looked headed for a routine victory before the match was suspended by rain in the third set on Wednesday but the former U.S. Open champion couldn't find the same rhythm on Thursday.
"Yesterday he was playing so, so good, and hitting the ball so hard that I couldn't do anything," the 82nd-ranked Pella said. "So the rain helped me a lot."
He's reached the third round of a Grand Slam for the first time.
Cilic was runner-up to Roger Federer last year and showed great form by beating Novak Djokovic in the Queen's Club final last month.
His early exit opens up Federer's path to the final even more, with No. 8 Kevin Anderson now the highest-seeded player left in the Swiss star's side of the draw after No. 6 Grigor Dimitrov lost in the first round.
Frances Tiafoe, a 20-year-old American, reached the third round at a Grand Slam tournament for the first time, beating Julien Benneteau of France 4-6, 6-3, 6-4, 6-2 at Wimbledon with the help of 22 aces.
The 52nd-ranked Tiafoe produced 52 winners and only 14 unforced errors while eliminating the 36-year-old Benneteau.
Tiafoe upset the 30th-seeded Fernando Verdasco in the first round.
Ninth-seeded John Isner hit 64 aces and saved two match points to reach the third round of Wimbledon for the fourth time.
Isner beat Ruben Bemelmans 6-1, 6-4, 6-7 (6), 6-7 (3), 7-5 in a match that had been suspended by rain on Wednesday.
Isner's ace total is the third-highest ever at Wimbledon — behind his own record in a three-day epic against Nicolas Mahut in 2010, which went to 70-68 in the fifth and is the longest tennis match in history. Isner had 113 aces in that match and Mahut hit 103.
Isner faced two match points against Bemelmans at 5-4 in the fifth set but held and then broke in the next game.
He was given a code violation in the fourth-set tiebreaker on Wednesday after losing his cool following a video review that went against him.
It was Isner's first win in a five-setter at Wimbledon since the Mahut match. He has never reached the fourth round at the Grand Slam tournament.
Eighth-seeded Kevin Anderson of South Africa beat Andreas Seppi to set up a third-round meeting with Philipp Kohlschreiber of Germany at Wimbledon.
The hard-serving Anderson hit 34 aces against the Italian to win 6-3, 6-7 (5), 6-3, 6-4.
The 25th-seeded Kohlschreiber ousted Gilles Muller of Luxembourg 7-6 (6), 7-6 (4), 7-6 (3) in a match that featured no breaks of serve.
Stan Wawrinka couldn't muster another comeback at Wimbledon, losing to Italian qualifier Thomas Fabbiano 7-6 (7), 6-3, 7-6 (6) in the second round.
The match was suspended because of rain on Wednesday with Wawrinka leading 6-5 in the third set, but Fabbiano wrapped up the victory quickly to equal his best Grand Slam result by reaching the third round.
Wawrinka, whose ranking has fallen to 224th following knee surgery, came from a set down to upset sixth-seeded Grigor Dimitrov in the first round for just his second Grand Slam victory since last year's Wimbledon.
Former Wimbledon finalist Angelique Kerber had to come from a set down to oust American qualifier Claire Liu in the second round.
The 11th-seeded Kerber broke decisively for a 4-3 lead in the third set before serving out a 3-6, 6-2, 6-4 victory against the 18-year-old Liu, the youngest player in the tournament.
Kerber lost the 2016 final to Serena Williams.
Liu is in her first senior Wimbledon draw and faced a top-10 ranked player for the first time. At No. 237, Liu was the lowest-ranked woman to make the second round.
Another Wimbledon finalist, Eugenie Bouchard of Canada, lost to 17th-seeded Ashleigh Barty 6-4, 7-5.
Bouchard was runner-up in 2014 to Petra Kvitova.
Play is underway on Day 4 at Wimbledon.
The 11th-seeded Angelique Kerber is among the early starters at the All England Club, playing American qualifier Claire Liu.
Later, top-ranked Rafael Nadal and Simona Halep are in action, while third-seeded Marin Cilic will try to wrap up a match that was suspended by rain on Wednesday.
Three-time champion Novak Djokovic will be in slightly unfamiliar surroundings as he tries to reach the third round at Wimbledon.
The 12th-seeded Serb is scheduled to play on No. 2 Court when he faces Horacio Zeballos of Argentina on Thursday, having grown more accustomed to appearing on the larger Centre Court and No. 1 Court at the All England Club.
Top-ranked Rafael Nadal and British hopefuls Johanna Konta and Kyle Edmund will be playing on Centre Court instead, while women's No. 1 Simona Halep and last year's men's runner-up Marin Cilic are on No. 1 Court.
Meanwhile, Stan Wawrinka has to erase a two-set deficit against Thomas Fabbiano to advance. Their second-round match was halted by rain on Wednesday with Fabbiano leading 7-6 (7), 6-3, 5-6.
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