Home hopes Zheng and Wang through to last-eight in Wuhan Open
Fifth seed Wang ousted US Open finalist Jessica Pegula 6-3, 7-5 while Olympic champion Zheng rallied past Canada's Leylah Fernandez 5-7, 6-3, 6-0.
Top-seeded Aryna Sabalenka, a two-time Wuhan champion, and freshly-crowned China Open champion Coco Gauff also advanced to the quarter-finals.
Zheng has had an incredible stretch of results since losing in the Wimbledon first round in July, winning 22 of the 25 matches she has contested.
And the world number seven paid tribute to retiring men's tennis great Rafael Nadal for inspiring her during difficult moments.
"I've watched his matches since I was a kid," said Zheng.
"There's lots of memories. Even now sometimes I will search Rafael Nadal and watch his old matches when he had 19 years old, 20, when he was at his prime.
"He inspires me a lot. Sometimes when I'm at a difficult moment, I will think how strong is Rafael Nadal's mentality in the tennis.
"I think that's sad to hear (Nadal retirement) because I really wanted to watch him more on the tour."
'Tricky style'
The 22-year-old was made to work in her last-16 clash, needing two hours and 29 minutes to see off Fernandez, also 22.
Zheng, who is inching closer to a qualification spot at the season-ending WTA finals in Riyadh, will square off with Italian third seed Jasmine Paolini for a semi-final berth.
Earlier in the day, Wang upset second seed Pegula to reach her first ever WTA 1000 quarter-final.
Wang, 23, punished Pegula's second serve, breaking the American four times for just the second top-10 victory of her career - both against Pegula this season.
"I put a lot of pressure on her with my returns. That was really good. That was the highlight of this match," said 51st-ranked Wang who next plays Russia's Ekaterina Alexandrova.
Belarus' Sabalenka avoided an upset, pulling through 1-6, 6-4, 6-0 against Kazakh Yulia Putintseva, to maintain her perfect record at the tournament with a 14th straight win.
The world number two struggled on serve for a set and a half against Putintseva, but reeled off the last nine games to set up a last-eight showdown with Magdalena Frech, who beat Beatriz Haddad Maia in straight sets.
"Yulia is one of those players who can be really annoying on court. Her style is tricky and she definitely makes you work for it if you want to win a match against her," said Sabalenka.
Gauff extended her current winning streak to eight matches with a routine 6-4, 6-1 victory over Ukrainian 13th seed Marta Kostyuk.
The American dropped just nine points on serve during the clash and was a perfect 5/5 on break point opportunities.
Fourth-seeded Gauff next plays Poland's Magda Linette.
