FC Barcelona's positive start under Ronald Koeman had produced two wins and seven goals without reply in their first two matches of the season, but that positive start was halted as they were held 1-1 at home to Sevilla on Sunday evening.
The ITTF revealed that Zhu has pulled out of the Women's World Cup due to health issues. Sun is also scheduled to play at the 2020 ITTF Finals.
The 2018 champion lost to Anisimova in the quarterfinals in Paris last year, but this time the Romanian needed only 54 minutes to complete a convincing victory.
Colombia will host Venezuela in Barranquilla on October 9 before facing Chile in Santiago four days later.
Also missing will be injured left-back Nilson Loyola and influential winger Edison Flores, whose club DC United refused to release him because of a mandatory 14-day self-quarantine for those returning to the United States capital from abroad. In addition, forward Jefferson Farfan is in doubt for the matches after re-injuring his troublesome left knee.
Swiatek is to face another unexpected winner from the fourth round - Martina Trevisan, as the world No. 159 stunned another title favorite Kiki Bertens 6-4, 6-4 in a later match on Court Suzanne-Lenglen.
The last set became a lop-sided affair for Tianjin, which went on a 12-4 run to pull away and kept the advantage until the end.
Growing infection figures around Cologne's venue are forcing Germany to play behind closed doors. Simultaneously, approval figures among German supporters decrease.
"We didn't deal well with some details in the first half and conceded many errors," added the Chinese international.
Sunday's win and the midweek victory against Valladolid were largely thanks to goalkeeper Thibaut Courtois, who produced man of the match performances in both games to keep Madrid's rivals at bay.
In women's actions, top seed Simona Halep took sweet revenge on her opponent from last year's French Open defeat, trouncing American teenager Amanda Anisimova 6-0, 6-1 to progress.