Sabalenka will play the winner of a match between American Madison Keys and Wimbledon champion Marketa Vondrousova.
"I'm super happy with the win against her... super happy with the performance," said Sabalenka, who lost in the semi-finals in her previous two U.S. Open appearances.
Zheng improved in the second set, forcing Sabalenka to run back and forth along the baseline as she showed finesse to triumph in a 21-shot rally in the fifth game.
"In the second set she start playing better, serving better.
"I'm super happy that even though she tried to play more aggressive, I was able to keep my level."
Persons:
China's Qinwen Zheng, Brendan Mcdermid, Sabalenka, Zheng Qinwen, pummelled, Zheng, Marketa Vondrousova, Amy Tennery, Ed Osmond
Organizations:
Tennis, U.S ., Australian, Madison Keys, Wimbledon, U.S, Thomson
Locations:
Flushing Meadows , New York, United States, Belarus, Belarusian, Flushing Meadows, New York