Simona Halep was ready for a vacation.
Karen Khachanov, Russia, def. Frances Tiafoe, United States, 4-6, 4-6, 7-6 (3), 6-2, 6-1.
Later Saturday, three-time champion Novak Djokovic plays his first match this year on Centre Court against Britain's Kyle Edmund.
Ernests Gulbis, Latvia, def. Alexander Zverev (4), Germany, 7-6 (2), 4-6, 5-7, 6-3, 6-0.
His next round rival will be Jiri Vesely of Czech Republic.
Juan Del Porto and Milos Raonic both rolled overtheir opponents to move on to the fourth round.
Dominika Cibulkova, Slovakia, def. Elise Mertens (15), Belgium, 6-2, 6-2.
Alison Van Uytvanck backed up her impressive victory over Muguruza with an assured 6-2 6-3 success against 28th seed Annett Kontaveit.
Angelique Kerber (11), Germany, def. Naomi Osaka (18), Japan, 6-2, 6-4.
Antonio Conte takes Chelsea training amid uncertain club future
Roman Abramovich has personally called Napoli's Aurelio De Laurentiis in a bid to speed up an agreement over Maurizio Sarri . The Serie A club have been reluctant to let their manager go - despite hiring Carlo Ancelotti as their new boss.
Australian 26th seed Daria Gavrilova crashed out 6-3 6-1 to Aliaksandra Sasnovich of Belarus and Spain's Carla Suarez Navarro was another casualty, the 27th seed turfed out 6-1 7-6 (7/3) by Belinda Bencic of Switzerland. I was fighting till the end for every ball. I think because I was exhausted, because I'm exhausted, I couldn't stay focused for every ball. "Mentally, I was exhausted". But I am too exhausted, I was too exhausted, I have pain everywhere. "My muscles are gone".
The path looks increasingly clear for 36-year-old Serena Williams to challenge for an eighth Wimbledon title in only her fourth event since giving birth last September.
World number one Rafael Nadal, who has retained his top ranking by beating Australia's Alex de Minaur in the third round of the ongoing Wimbledon championship, said that he prefers to be number one rather than number two. "Because every day, something unusual is happening in the draw".
A year ago she knocked seventh seed Johanna Konta out of the French Open.
"It's fantastic. I was 2-5 down in the final set but the crowd pushed me to fight".
With the momentum well and truly on her side, Hsieh broke again when Halep failed to return a big forehand and the Romanian was unable to rescue the situation.
"It is fantastic", Hsieh said.
Cunning drop shots, often played with two hands on the racket, delicate slices and laser-like flat groundstrokes that hugged the turf kept Halep continually off balance. I will not find excuses about this match, she deserved to win.
"Inside, I was, like, dying", the 24-year-old Belgian said.
This marked Hsieh's first career success in making it to the fourth round of the grand slam in London.