Guangzhou, Guangdong, China, 16 September 2014 |

Sam Stosur’s difficult season hit another snag when she was upset by world No.251 Yafan Wang in her opening match at the Guangzhou International Women’s Open.

The Chinese player came back from a set down to defeat the top seed and former US Open champion in the first round 2-6 6-2 6-2.

Stosur served seven double faults and was broken on four occasions during the match.

She had also lost to a 406th-ranked qualifier in Stanford back in July and while Stosur did reach the semifinals at New Haven she failed to progress past the second round at the US Open.

Australia’s No.1 player, ranked 20th in the world, may not be for much longer with plenty of points to defend from tournaments at the back end of last year.

Stosur had her best run towards the end of 2013 where she won a tournament and finished runner-up in two others.

With compatriot Casey Dellacqua in good form, ranked No.30 in the world and enjoying a first round win in Tokyo over Sabine Lisicki, she may yet be Australia’s highest rated woman by year’s end.

Elsewhere in the first round, fifth seed Zarina Diyas was eliminated after being defeated 6-4 6-1 by Ling Zhang of Hong Kong.

The exodus of seeds continued when No.4 player Bojana Jovanovski fell to Monica Niculescu, who emerged as a comfortable 6-2 6-2 winner.

Another Chinese hope, Kai-Lin Zhang, defeated No.7 seed Jana Cepelova, meaning six of the top eight had been eliminated in the first round.