Zhejiang's Wang Shun clinched gold in the men's 200m individual medley in 1:56.83, leading silver medalist Deng Ziqi from Guangdong by around five seconds. Liu Zongyu from Shandong took the bronze.
Third seed Thiem was competing for the first time as a Grand Slam winner and followed his fourth win in as many head-to-head clashes against Cilic. The 27-year-old improved his record at Roland Garros to 25-6.
Ji Xinjie from Shandong secured the gold in the men's 400m freestyle in 3:48.87, with Hubei's Zhang Ziyang and Ji's teammate Hu Jia rounding out the top three.
"[I'm] struggling to walk so that's a tell-tale sign that I should try to recover," she added.
Guardiola fielded new signing Nathan Ake and youngster Eric Garcia, neither of whom is six feet tall.
"Mistakes are human, but I don't see how the umpire can miss that. She didn't see a double bounce," the 2017 French Open quarterfinalist added.
Joan Simun Edmundsson's sole goal was enough to ensure Arminia Bielefeld a 1-0 win over Cologne, and RB Leipzig played out a 1-1 draw with Bayer Leverkusen. Enditem
Stage One involves 32 groups of four players, with the player who tops each group progressing to Stage Two.
Schalke will probably decide its future steps at Monday's board meeting.
The Serb frequently used drop shots throughout the game, just as he did during his Rome title run last week.
"My goal was to reach the podium, but I didn't expect to win the title," said Song.