The defending champions, who had lost their first two games of the new season, have now bounced back with four consecutive wins to move up to second place.
With several different players contributing in offense, Jiangsu went on another 16-3 run to start the second quarter to extend its advantage to almost 30 points, which gave little room for Shaanxi's fightback. Shaanxi came no closer than 14 points during the entire second half.
Shanghai led by as many as 35 points in the final period.
"But I take it as a very positive thing. I am playing quite well to win against a player like Stefano today with this score.
"We've had an unbelievable group of players over the last two seasons and a squad of great people. I will miss them all hugely...I'd also like to say a massive thanks to the club for considering mine and my family's future and allowing me to make this move."
Newly promoted Elche and Huesca drew 0-0, although Huesca was the better side as Elche failed to get a shot on target.
Growing infection figures around Cologne's venue are forcing Germany to play behind closed doors. Simultaneously, approval figures among German supporters decrease.
"To stand in his way would not be just reward for the service he has given us, and we wish him the best."
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.
"We had a poor start as our players didn't show enough mentality, but I'm satisfied with the players' performance in the following three quarters," Shaanxi coach Jiang E'Ying commented.
"We executed the coach's tactics well," she explained.