Petrova forced out

Petrova has been struggling with the injury since last month

Seventh seed Nadia Petrova withdrew from the Pan Pacific Open in Tokyo without hitting a ball after failing to recover from injury.

The Russian strained her left buttock during the final of the Australian Hardcourt Championships last month.

She also missed the Canberra Classic before losing to Hungary's Aniko Kapros in the Australian Open first round.

Petrova's replacement, fellow Russian Alina Jidkova, was beaten 7-5 6-2 by American Laura Granville.

Eighth seed Daniela Hantuchova was made to work hard as she won 6-1 6-7 (7-9) 7-5 against Australia's Alicia Molik.

The Slovak squandered a match point at 7-6 in the second set tie-break and twice had to recover from a break down in the decider.

It gave Hantuchova a measure of revenge for her second-round defeat by Molik at the Australian Open two weeks ago.

"It felt great," said Hantuchova. "It was the third time we played each other and Alicia was a sort of becoming a nightmare for me."

Hantuchova will now face Russian teenager Maria Sharapova, who cruised through with a 6-1 6-1 victory over Japan's Yuka Yoshida.

Magdalena Maleeva of Bulgaria recovered from the loss of the first set to see off American Lisa Raymond 4-6 6-2 6-3.

Japan's Saori Obata beat Julia Vakulenko of the Ukraine 7-5 6-3 and Russia's Tatiana Panova overcame Zheng Jie of China 6-4 6-3.

Venezuela's Maria Vento-Kabchi beat Russia's Elena Likhovtseva 6-3 7-6 (7-5).

Katerina Srebotnik of Slovenia withdrew from the tournament with a torn muscle in her right elbow.