Keeper Han Jiaqi made key saves to keep the three points for R&F, with Jianye unable to score in the second half.
"Serena is Serena," Sakkari said after advancing earlier Saturday by beating 19-year-old American Amanda Anisimova 6-3, 6-1. "You have to come up with some great tennis. Otherwise there is no chance against her."
Barcelona insisted that he had to pay his 700-million-euro release clause.
Although Messi will remain at the Camp Nou until he can leave as a free agent, fans are worried at the interview in which he explained how he felt in recent months.
Elsewhere, Poland, who were playing without leading striker Robert Lewandowski, registered their first victory of the tournament in Zenica.
"The Premier League confirms that it has today terminated its agreements for Premier League coverage in China with its license in that territory, the Premier League will not be commenting further on the matter at this stage," read a statement.
"At the start of the season I was in great shape physically and mentally, I was ready to dominate track but unfortunately COVID-19 slowed me down. With Ostrava meeting opportunity now here, I will give it my best," said Chelangat who still harbors an Olympic Games ambitions next year.
The midfielder then posted a message to fans on social media as he prepared to undergo surgery to repair his ACL.
Armin Hodzic (R) of Bosnia and Herzegovina (BiH) vies with Tomasz Kedziora (1st L) of Poland during the UEFA Nations League football match between BiH and Poland in Zenica, Bosnia and Herzegovina, on Sept. 7, 2020. (Photo by Nedim Grabovica/Xinhua)
"It's going to be one of the young guys, I think, if you count Dominic Thiem as a young guy, as well. He obviously has a chance to win. Now I think it is the time where it gets really interesting. We'll see where we go from here," added the German.
Spain now move top of Group A4, one point ahead of second-placed Ukraine. Germany are third on two points after they lost 1-0 to Switzerland.