Carla Suarez Navarro's dismal run of form continued at the Japan Women's Open as she was dumped out in the first round by Kateryna Bondarenko in a 6-4 6-4 defeat.

Suarez Navarro enjoyed a fine start to 2015, climbing into the top 10 and reaching finals in Antwerp, Miami and Rome.

However, the Spaniard exited in the first round in Toronto, Cincinnati and at the US Open and her barren run continued in Tokyo on Tuesday.

Bondarenko, 73 places below the top seed who is now ranked 12th, failed to hold her nerve when serving out for the opener at 5-3 but quickly recovered to break straight back and take a one-set lead.

It was a similar story in the second. Bondarenko again had a 5-3 lead only to relinquish the break, but Suarez Navarro - handed a wildcard for the tournament - again failed to make the most of the reprieve and was sent packing.

Second seed Zarina Diyas earned her place in the next round with a 6-4 6-4 triumph over Kiki Bertens.

Alison Riske and Johanna Larsson - the fourth and fifth seeds respectively - had alternating fortunes after one-sided sets to start their campaigns.

American Riske fell to a 0-6 6-4 6-1 loss to China's Zheng Saisai, while Sweden's Larsson fended off a hot start from Zheng's countrywoman Wang Qiang to win 0-6 6-3 6-3.

Hsieh Su-wei scalped eighth seed Polona Hercog 6-1 5-7 7-5.

Qualifier Risa Ozaki stunned former world number 32 Bojana Jovanovski 6-1 6-1, the world number 142 advancing to a clash with sixth seed Christina McHale.

Other qualifiers did not fare as well - Alexandra Panova, Naomi Osaka and Hiroko Kuwata all falling at the first main-draw hurdle.

Australia's Jarmila Gajdosova downed Panova 6-3 6-4, American Irina Falconi got past Osaka 5-7 7-5 6-3 while Japanese wildcard Nao Hibino defeated Kuwata 3-6 6-4 6-4.

Magda Linette had a 6-3 6-2 victory over Lauren Davis, while Kurumi Nara joined locals Ozaki and Hibino in the second round with a 6-1 6-4 dismissal of Andreea Mitu.