World number one Maria Sharapova responded to a scolding from her coach to beat Italy's Francesca Schiavone 7-5, 2-6, 6-1 and reach the quarter-finals of the Pan Pacific Open on Thursday.

The 19-year-old Russian twice fought back from a break down to take the opening set but suffered a total meltdown in the second, earning her a ticking off from coach Michael Joyce.

With on-court coaching allowed in Tokyo, Joyce did not mince his words when he sat next to a sulking Sharapova at the change of ends.

"Find a way to win!" he snapped at her.

Still scowling, Sharapova hit back with steely resolve, storming through the deciding set to book her place in the last eight of the $1.3 million tournament.

Sharapova, beaten by Serena Williams in the final of the Australian Open at the weekend, faces Japan's Ai Sugiyama in the last eight.

Local favourite Sugiyama, making her 15th successive Pan Pacific appearance, advanced after beating Russia's Maria Kirilenko 3-6, 6-1, 6-3.

Defending champion Elena Dementieva also powered through, the third seed shrugging off late jitters to beat fellow Russian Elena Likhovtseva 6-3, 7-5.

Dementieva plays Roberta Vinci in the quarter-finals following the Italian's easy 6-3 6-0 victory over Frenchwoman Severine Bremond.

Serbian fourth seed Jelena Jankovic, who began her year by winning her second WTA Tour title in Auckland, also advanced in style by overpowering China's Zheng Jie 6-4, 6-0.

Fifth seed Ana Ivanovic will face her fellow Serb in the quarter-finals after beating Italy's Mara Santangelo 4-6, 6-1, 6-2.

Australia's Samantha Stosur completed a miserable day for China with a 6-2, 6-4 upset victory over sixth seed Li Na. Stosur plays former world number one Martina Hingis in the last eight.