Four-times Tokyo winner Martina Hingis fought back to beat third seed Nathalie Dechy 4-6, 7-5, 6-2 and remain on course for a semifinal showdown with defending champion Sharapova.

The Russian world number four's victory came with the minimum of fuss, Sharapova converting her first match point with a blistering backhand pass off a sharp Raymond volley.

"When I had the opportunity to win, I did," Sharapova told reporters. "But I think I will play better. If I keep improving I definitely feel confident I can win it again."

In contrast, Hingis was forced to dig deep after an erratic start.

The former world number one returned to tennis last month, reaching the last eight of the Australian Open in her first grand slam since injury forced her into early retirement in 2002.

Hingis struggled to hold serve for the first set and a half but dug in to force a third set as Dechy's nerve began to waver.

The "Swiss Miss" dominated her French opponent in the deciding set, showing glimpses of the form that brought her five grand slam singles titles between 1997 and 1999.