Guoan extended the lead just three minutes after the break as Teda's clearance went into the path of Renato Augusto who bent a curler into the top corner.
The nation's top comprehensive sports gala in 2021 will attract around 14,000 athletes in 501 events across 41 sports.
Meanwhile the arrival of the experienced Manuel Pellegrini at Betis promises the stability that has been missing at the club in recent seasons and that alone should improve a team that underperformed last time around.
Aymeric Laporte's positive test for COVID-19 means he could miss the start of the campaign, but the Frenchman is vital to City's options.
Evergrande broke the deadlock in the 40th minute with a moment of magic, as Paulinho dribbled past several defenders at the edge of the box, unleashing a rocket that went beyond an out-stretched Wang.
"We (the Chinese women's volleyball team) hope that the Olympic Games will be held successfully because we have been fighting for this for four years," said the 25-year-old.
Saturday saw Arsenal kick off the season with a comfortable 3-0 win away to Fulham, with new signing Willian turning in a man-of-the-match performance.
Chemnitzer FC took the reins and disrupted Hoffenheim's build-up work in the opening stages, forcing Hoffenheim goalkeeper Oliver Baumann into action twice with early chances.
After the half time, the "Herthaner" came out with their guns blazing whereas Braunschweig kept eleven men behind the ball to protect the lead.
Evergrande doubled the lead in the 69th minute with a stunning free kick from Ai, two minutes after his tap-in was ruled out due to off-side.
In the men's quarterfinals, second seed Dominic Thiem of Austria eased past Australian player Alex De Minaur 6-1, 6-2, 6-4 while third seed Daniil Medvedev of Russia defeated compatriot Andrey Rublev 7-6(6), 6-3, 7-6(5).