Third seed Williams essayed a signature comeback and served 12 aces to edge past her American compatriot Stephens 2-6, 6-2, 6-2 in one hour and 43 minutes.
"I was a little bit in shock," Carreno Busta said. "The rules are the rules. The referee and the supervisor did the right thing, but it's not easy to do it."
In the second half, Bosnia coach Dusan Bajevic brought on Edin Dzeko as the side's second striker, but Poland's domination continued, and Kamil Grosicki scored the winning goal in the 67th minute.
Belarus's Victoria Azarenka advanced into the quarterfinals after rallying past Karolina Muchova of the Czech Republic 5-7, 6-1, 6-4.
It was also a disastrous race for Red Bull, with Max Verstappen retiring from the midfield with engine trouble, and Alex Albon finishing down in 15th after a scrappy performance in which he received a five-second penalty for impeding Romain Grosjean's Haas.
Williams said: "I tried to stay calm and be more serene after the loss of the first set. I knew it was important for me just to keep trying, just to keep going."
Both sides had chances to break the deadlock in the first half but missed them all. Shanghai Shenhua midfielder Cao Yunding's left-footed shot hit the post in the seventh minute. Shenzhen almost scored the opener in the last minutes going into the halftime break when Ole Selnaes' free kick was also denied by the crossbar.
In the constructors' standings, Mercedes stay out in front with 281 points. Red Bull remain second with 158 points, while third-placed McLaren now have 98 points after their best result of the year.
Tokyo 2020 president Yoshiro Mori has said that the delayed Tokyo Olympics could not be held next year if the COVID-19 pandemic continues as it is. He also said that the Games will have to be canceled if it could not be held next year.
Gu also says that exercising makes him feel young and healthy.
In the last 10 minutes, both sides tried hard to find the net again but failed either. In the 88th minute, former Italian international Eder almost made it for Jiangsu, but his shot was saved by the goalpost. Enditem