Ferreira, who replaced former Real Madrid midfielder Lucas Silva just after the hour mark, struck in the 92nd minute with a glancing header after an Alisson de Freitas corner.
"We gave up our own advantage in tactics, only to let Jiangsu play its way comfortably," said Shanghai head coach Wang Zhiteng.
"One can't understand it," Flick said when criticizing UEFA's decision to choose the venue and allowing up to 20,000 spectators.
Media reports speak of deep divisions between him and his players.
Meanwhile, the men's and women's singles draw was also completed on Thursday, as men's title favourites Rafael Nadal and Novak Djokovic were drawn into different halves, meaning they cannot face each other before the final.
In his letter, published on social media, Messi said that Suarez had been "thrown out" by FC Barcelona.
Prior to the game, both sides needed a victory to secure them a top four berth with only two games left in the Suzhou division.
Peng Xinli broke the deadlock in the 37th minute as the midfielder burst into the box and prodded into the net from close range.
The pay-tv stations covering the game, Sky and DZAN, announced they would not be sending reporters to Budapest but instead would commentate on the game from Germany.
The following fixtures are scheduled for Saturday: Borussia Monchengladbach host Union Berlin, Bayer Leverkusen face Leipzig, Mainz meet newly-promoted Stuttgart, Augsburg clash with Borussia Dortmund, newly-promoted Arminia Bielefeld take on Cologne, and Schalke face Werder Bremen. Enditem
The match went ahead and West Ham defeated their League One rivals 5-1 with assistant Manager Alan Irvine under charge.