Top seed Stosur crashes out in first round of Guangzhou WTA

Four of the top five seeds including number one pick Samantha Stosur crashed out of the $500,000 WTA Guangzhou Open in the first round, as the former US Open champion's poor run of form continued.

Four of the top five seeds including number one pick Samantha Stosur crashed out of the $500,000 WTA Guangzhou Open in the first round on Tuesday, as the former US Open champion's poor run of form continued.

Australian Stosur lost to home wildcard entry Wang Yafan 2-6, 6-2, 6-2, making seven double faults in a two-hour, three minute match.

On a day of shocks, fourth seed Bojana Jovanovski of Serbia lost to Romanian Monica Niculescu 6-2, 6-2, while Zarina Diyas of Kazakhstan, seeded five, crashed out to Hong Kong's Zhang Ling 6-4, 6-1.

Third seed Sloane Stephens of the US lost 6-3, 4-6, 6-4 to Spain's Silvia Soler-Espinosa in the day's last match.

Stosur won the US Open in 2011, a season which saw her climb to number four in the rankings.

But she is now at 20 after failing to get past the semi-finals of any of the 18 tournaments she has competed in so far this year.