Halep started with a break and grabbed a 4-1 lead to win the first set in 33 minutes before repeating her giant-killing act in the second to ice the win in 72 minutes with five breaks of serve.

Sharapova, who returned in late April from a 15-month doping ban, had beaten the Romanian in the first round of the US Open a month ago. "She played an incredible match, probably the best she's played against me in all of our previous meetings," Sharapova said.

"I wasn't as sharp. I wasn't seeing the ball as well. "I wasn't moving up and down as well as I have been against her. She was hitting the ball consistently, not making a lot of unforced errors, her service percentage was quite high. She did all the right things."

In second-round play, French Open champion Jelena Ostapenko put out Australian Samantha Stosur 6-3, 7-5 as the Latvian earned a 40th win of her best career season. Ostapenko served notice of her intentions with a break of the 33-year-old Stosur to start their match, with the ninth seed keeping up the pressure all the way to victory.

France's Caroline Garcia beat Belgian Ele Mertens 7-6 (7-4), 6-4 while China's Peng Shuai knocked out Monica Niculescu 6-3, 6-2. On the men's side, Australian Nick Kyrgios booked into the quarters 3-6, 6-2, 6-2 over German Mischa Zverev. The eighth-seeded Kyrgios advanced with 11 aces and four breaks of serve in 82 minutes.

“I knew it was going to be tough,” Kyrgios said. “He plays a very old-school type of tennis, likes to come forward a lot. “I got broken early in the first, I had to loosen up and find my rhythm a little bit. I started serving much better, started just relaxing. "I knew I was going to feel pretty comfortable out there. Obviously just really happy to get through.”

The Aussie improved his season record to 29-14 with the victory in the Chinese capital. Kyrgios, looking for his fifth semi-final of 2017, will next face Belgian Steve Darcis, a winner over Serb Dusan Lajovic 6-3, 6-4.

Darcis has been pulling his season together after poor performances at mid-year as he won just two of nine matches over the summer. But coming to Asia seems to have made a difference for the number 73, who won a round last week in Wuhan following a five-set challenge he gave to Kyrgios in the Davis Cup semi-finals which Belgium won.