The title is the 27-year-old Thiem's first Grand Slam trophy after three previous defeats in finals of tennis majors.
Elsewhere, SIPG established the advantage in the stoppage time of the first half, when Ricardo Lopes contributed a long diagonal pass from the right flank into the box, which was stopped by striker Lv Wenjun in front of the goal. Marko Arnautovic smashed in a volley in chaos.
Ceara moved to ninth with 13 points from 10 matches while Flamengo slipped to fifth, three points behind Internacional.
Leicester City were last season's surprise package with their fifth place finish and the challenge for coach Brendan Rodgers will be to get near repeating that, and to get close he needs Jamie Vardy to keep hammering home the goals.
Both sides struggled to avoid relegation last season and neither look stronger after a summer in which Eibar have lost players such as Fabian Orellana, De Blasis and Gorka Escalante while Rafinha, Jeison Murillo, Fiodor Smolov and Pione Sisto have all left Celta.
Fernandinho equalized after dribbling into the box and beating Hebei goalkeeper Bao Yaxiong, finishing a counterattack in the 29th minute.
"From the perspective of a 90-minute game, it is reasonable for Guoan to seal the victory. I still want to praise all the team members because they showed high morale on the pitch," said Teda head coach Wang Baoshan.
Hunan now ranks third in the standings behind Qingdao and Ruichang Biyuan. First-placed Qingdao breezed past Xiamen 4-1 on Thursday, while Ruichang overcame Anhui Souyu 3-2.
"A match like today, I just feel like Pironkova was serving well, she was hitting winners everywhere," Williams said. "Maybe I wasn't being aggressive enough. So I think it's more or less me adjusting my game in the second set and coming back and just trying to do better."
Hence, 1860 came by chances in the early stages as veteran Sascha Molders pulled wide from inside the box in the sixth minute before defender Martin Hinteregger had to tackle Molders to deny another chance eight minutes later.
Sunday kicked off with Christian Tello's 94th minute goal giving Manuel Pellegrini a win in his debut as Betis coach and to ensure Pablo Machin begins his spell in charge at Alaves with a defeat.