Samantha Stosur faces the unenviable task of having to beat Maria Sharapova to advance to the semi-finals of the Pan Pacific Open.

While Stosur enjoyed a 6-4 7-5 win over Dominika Cibulkova to advance to the final eight on Wednesday, a much tougher target looms.

Sharapova, a 6-2 7-6 (7-5) winner over Lucie Safarova, is 10-1 in career meetings over Stosur – but the Australian was just glad to get this far after exiting in her opening match in Tokyo the past two years.

“It’s nice to be winning some matches here in Tokyo again,” she said.

“Today I thought I played really quite well, so I’m looking forward to the next one.”

Sharapova hadn’t played when Stosur spoke but the world No.9 made it clear another match-up with the Russian would be hard work.

“If I play Maria, then obviously we all know what she plays like and what she’s capable of,” Stosur said.

“She had a long match yesterday and if she gets through this match, then hopefully she’s a little bit tired.

“She’s one of the players I’ve struggled with in the past and only beaten her once, so it is always a really good challenge to play her.”

Two-time champion Sharapova finally found some rhythm to dispose of the stubborn Safarova, coming hard on the heels of needing more than three hours to beat qualifier Heather Watson of Britain on Tuesday.

“After the long match yesterday, I’m very happy to be able to win today,” Sharapova said.

“I was a little bit down in the second set and I’m just happy to win in two sets.”

Safarova, ranked 17th against Sharapova’s second in the world, came back from 0-3 down to 3-3 and then 4-4 before hitting a fine service return winner on break point to take a 5-4 lead in the second set.

But again neither could keep their serve in the following three games as the contest went to a tie-break.

Safarova again went down 0-3 in that before coming back to make it 4-4, but made a forehand error twice to give Sharapova a commanding 6-4 lead.

Safarova saved the first match point with an ace, but Sharapova calmly won the match by hitting an ace on her serve.

On a day of few surprises, defending champion Agnieszka Radwanska of Poland beat qualifier Jamie Hampton of the United States 6-4 6-3.

Sixth seed Sara Errani of Italy outclassed ninth seed Marion Bartoli of France 3-6 6-2 6-2, while fifth seed Angelique Kerber of Germany overwhelmed Urszula Radwanska of Poland 6-1 6-1.

Nadia Petrova of Russia defeated plucky Petra Martic of Croatia 7-6 (7-2) 6-7 (1-7) 6-4.