"I'm actually glad the crowd wants to get into it, because it means that the match is interesting," Novak Djokovic said.
"I saw I'm playing first match and was, like, wow, that's a little bit strange scheduling," Jelena Ostapenko said after bowing to Coco Gauff.
The Belarusian says she owes Swiatek gratitude, and looks forward to more battles with her.
"I think [Madison Keys is] a bigger hitter on tour than a Sabalenka or an Iga or even a Rybakina," said Jessica Pegula.
"I knew since he started to play on tour that he have amazing serve," Andrey Rublev said of Ben Shelton.
Wimbledon champion withdrew from US Open doubles to save her stiff shoulder for singles quarterfinal vs. Madison Keys.
The Pole is sad about losing her US Open title defense and the No.1 ranking, but believes she'll be back.