- Green Growth
- Your Consultant
|Semi-final push: Simona Halep returns against Zhang Shuai AFP/GLYN KIRK|
Halep, the seventh seeded former world number one, will face either Elina Svitolina, the eighth seed from Ukraine, or Karolina Muchova of the Czech Republic for a place in the final.
Zhang, bidding to become just the second Chinese woman to reach the semi-finals, led 4-1 in the first set and held four break points for a 5-1 lead.
"I fought hard in the first set, even if I was down 4-1," said 27-year-old Halep, a former French Open champion.
"I knew I had to be strong, play aggressive as much as possible and I did it great.
"I have energy, I feel fresh, I feel healthy, I feel confident when I step on the court."
Romania's Halep last made the last-four in 2014 when she was beaten by Eugenie Bouchard.