Zheng is down to 121st in the world rankings after elbow surgery and was forced to qualify for the US Open, but she is on her way back to the form that made her a world number four and Olympic champion in Paris 2024.
The start of the match with world number eight Swiatek was anything but good, however. Down 0-5 and facing set points, the Chinese player won seven straight games and won both the set and later the match.
In the third round, she did the same thing - but then turned the tables from 0-5 down in the tiebreaker against Madison Keys of the US.
"It's not just luck. I didn't start very well, but I found the rhythm. I just focused on point by point," says the Chinese player in the stadium interview on HBO Max.
In the quarterfinals, world number two Yelena Rybakina of Kazakhstan awaits, after she defeated two-time US Open champion Naomi Osaka of Japan, 6-1, 6-4.
