Shanghai's hope of leveling the game was shattered as Barbra Banda's shot in the 87th minute hit the woodwork and bounced off.
With the result, Union Berlin move up to third place in the standings, while Mainz stay 17th after suffering their third straight defeat of the new season.
Colombia will face Venezuela in Barranquilla on Friday and Chile in Santiago four days later in the opening matches of South America's 2022 World Cup qualifying tournament. Enditem
Two-time Grand Slam winner Kvitova had to bounce back from 1-5 down in the opening set against Canada's teenager Leylah Fernandez to set round-of-16 clash with Zhang.
Meanwhile, Sport Recife won 2-1 at Bahia, their third successive Serie A victory. Hernane and Marcao were on the scoresheet for the visitors while Matheus Saldanha netted for Bahia.
Esteghlal had been linked with former Werder Bremen coach Alexander Nouri but they failed to reach an agreement with the German-Iranian coach due to financial disagreements.
"We are in a very strange situation, after a lot of months without much tennis, especially for me, that I didn't play in America, I don't know if it's a positive thing or a negative thing," Nadal said when asked how important it was to keep the early-round matches short and sweet.
"We executed the coach's tactics well," she explained.
"I'm very, very happy to be in the semifinals again and here at Roland Garros," Nadal said on court. "No doubt that this is the most important place for me and the most beautiful place to play."
Jiangsu took to attacking the basket from the paint early on, before going up 20-9 on a 14-0 surge.
The injury means that Alba will be forced to pull out of the Spanish national team squad for the forthcoming friendly game in Portugal and the UEFA Nations League ties against Switzerland and Ukraine.