Frustrated Sabalenka wins opener to launch Beijing title bid

The top seed and world number two will face the 29th-seeded New Zealander Lulu Sun or Ashlyn Krueger of the United States in the third round in Beijing.

Fresh from winning the US Open, the Belarusian made hard work of an opponent ranked 187 in the world and playing the biggest match of her young career.

The 22-year-old Mananchaya may have been inexperienced at this level but the athletic Thai refused to give up seemingly lost causes.

Mananchaya struggled though on serve and three-time major champion Sabalenka broke for a 4-2 first-set lead.

The Thai refused to be overwhelmed by Sabalenka's far greater power and she broke back immediately, to roars of approval from the Beijing crowd.

An error-prone Sabalenka could not get into her groove but created a first set point on the Thai's serve, only to put a straightforward volley wide.

She made no mistake on her second opportunity and then broke for 3-1 in the second set.

Sabalenka barely raised a smile at the end.

Also into the third round of the WTA 1000 tournament is third seed Jasmine Paolini but the Italian did it the hard way, fighting back to beat Denmark's Clara Tauson 1-6, 7-5, 6-4.

World number one and defending champion Iga Swiatek pulled out before the tournament because of "personal matters".