Shanghai's hope of leveling the game was shattered as Barbra Banda's shot in the 87th minute hit the woodwork and bounced off.
Five Inner Mongolia players recorded double digit points, as they dominated the game. Li Yueru made 12 out of her total 14 shooting attempts, taking home a game-high 28 points, along with 14 rebounds. Zhang Qifang added 14 points. Wei Wei and Yang Liwei contributed 12 and 11 points respectively.
"It's because I did a lot of things well. I played more aggressively than the previous days. I went to the net more often, and I hit a lot of winners," added the 12-time French Open champion, who needed only one hour and 35 minutes to see off his opponent.
"We played a bit tight at the start as it was our first game, but we never gave up, and finally won the game," Li said.
The previous best for the No.7 seed in Paris was the semifinals in 2012 when she lost to eventual champion Maria Sharapova 6-3, 6-3.
Tianjin coach Liu Hao admitted as a young team, his side have a gap to Shanghai in terms of skill.
It was short-lived joy for Berlin though, as Bayern took the lead again through Lewandowski, who tapped home his hat rick following Muller's assist inside the box in the 85th minute.
Luneng has been coached by Li since December 2017. He started working in Luneng's coaching team in December 2015 after he served as the head coach of the women's national team, coach of Qingdao Jonoon, and general manager of Shijiazhuang Ever Bright.
The French champions will kick off the continental campaign at home against Manchester United on October 20.
Shanxi had a 10-3 dash in the midway of the last quarter, bringing the game beyond Hebei's reach.
Shandong began to lose momentum after the interval, and Inner Mongolia scored many fast break points on turnovers. With a 30-point margin in hand before the last 10 minutes, Inner Mongolia met little challenge thereafter.