After a first-round bye, it took Sharapova three days to complete her first win on grass this year, a 6-0, 6-3 defeat of U.S. Fed Cup player Bethanie Mattek-Sands. She was then back on court for only 65 minutes for an even more impressive 6-3, 6-1 success against Alla Kudryavtseva, the fellow Russian who sensationally upset her at Wimbledon two years ago.
Both results proved encouraging for Sharapova, especially against Kudryavtseva, who briefly played as though she could spring another surprise, holding three points for a 4-1 lead with a double break of serve.
It required Sharapova to adopt a tenaciously positive attitude on an outside court in cold, blowy, and miserably overcast conditions.
She hit 11 aces and conceded only two points on serve in the second set in a performance which suggested that her service was regaining some of the power which was once a formidable barometer of her game, but which lost potency following a shoulder operation two years ago.
Next for Sharapova will be Kazakh qualifier Sesil Karatantcheva, if center court is ready on Friday. The main court was unavailable on Thursday _ despite no rain _ because the covers weren't big enough to accommodate the whole court, leaving the show court waterlogged.
Karatantcheva, a former French Open quarterfinalist who was two years back from a drugs suspension, completed her fifth win of the tournament by eliminating defending champion Magdalena Rybarikova of Slovakia 6-2, 6-7 (3), 6-2.
If the second-seeded Sharapova wins, she could play fourth-seeded Yanina Wickmayer, the steadily improving world No. 16 who won twice on Thursday against Laura Robson, the 16-year-old former Junior Wimbledon champion from Britain, and Tamarine Tanasugarn, the former Wimbledon quarterfinalist from Thailand.
Top-seeded Li Na of China beat Anne Keothavong of Britain 6-2, 6-4, then was tied with Angelique Kerber of Germany after two sets before darkness stopped play.
Also through to the quarterfinals were fourth-seeded Aravane Rezai of France, and American qualifier Alison Riske, ranked 192, who will face Wickmayer on Friday.