Zheng survives Andreeva scare to advance at US Open
Andreeva, the elder sister of teenage sensation Mirra, had already knocked out one Chinese player in Yuan Yue and was looking to reach the third round at Flushing Meadows for the first time in her career.
Despite Andreeva taking an early lead and then clinching the tiebreak, Zheng clawed her way back into the contest on the back of a solid first serve as the seventh seed finished the match with 36 winners and 20 aces.
"I started the match quite slow. Little by little I started to feel better in the reaction, in my serve," said Zheng, who was runner-up at the Australian Open this year.
"Honestly, today, I know (how) I entered the match wasn't the way I wanted but I'm glad I still fought until the end. I didn't give up, because she got a lot of chances in the second set."
Zheng started poorly, losing the first two games of the opening set and although she fought back with a break of her own, she was always playing catch-up as Andreeva surged ahead.
At 6-5 down, the Chinese number one served well to force a tiebreak but a third double fault in the set gave Andreeva the upper hand and the 20-year-old Russian did not look back, sealing the set when Zheng's backhand went wide.
Zheng rediscovered her rhythm in the second set and won five games in a row from 1-1 on the strength of a superb first serve to force a decider, while Andreeva made several errors.
Andreeva's struggles continued into the third set where one of her powerful returns went so wide it was caught by a spectator behind the chair umpire while Zheng began dealing in winners and aces.
By 5-2, Andreeva had thrown in the towel and Zheng wrapped up the match with two aces to move into the third round where she will play Germany's Jule Niemeier.
"When I lost the first set and after I see the crowd supporting me, I say to myself, 'Let's keep fighting, even if it's a difficult day'," Zheng added.
"I want to say thanks to the crowd who supported me today, that was an amazing atmosphere."