The 133rd-ranked wild card crushed the world No. 1 just weeks after Ivanovic surrendered only one set en route to the French Open title.
Signs of the Serbian's vulnerability were apparent as she saved match points in her 6-7 (2), 7-6 (3), 10-8 second-round win over 97th-ranked Nathalie Dechy. Ivanovic's flat forehand, her most explosive weapon during her Roland Garros run, did not faze Zheng, who fired back fast, flat shots to take charge early in rallies.
Hovering right on top of the baseline, Zheng, a 2006 Wimbledon doubles champion, used her compact swings to spit back deep drives that robbed Ivanovic of reaction time as she tried to transition to grass. Giving up nearly eight inches in height, Zheng played fearless tennis in scoring her first Top 10 win.
"I tried to play balls higher, to try to get under the ball and play with lot of spin. But I found it hard to get good timing," said Ivanovic, who converted just one of seven break point chances. "I made too many mishits, I think, as well. She played well. She served also very good. I found it hard to mix my serve. She was reading my serves very well. Even when I tried to kick it and bounce the ball high, she was still there on the ball."
Zheng continued a historic run in becoming the first Chinese woman to reach a Grand Slam singles semifinal.
"I believe [I could win], but I didn't believe I could win two sets," Zheng said.