Maria Sharapova came back from one set down to beat Heather Watson 6-7 (9/7), 6-3, 6-4 in the second round of the Pan Pacific Open in Tokyo on Tuesday.
Sharapova, who, along with Victoria Azarenka,had a first-round bye here, was stretched by the British youngster in the first set that she won in the tie-breakers.
The second-seeded Russian then came back strongly to claim the next two sets and move into the third round of the tournament.
12th-seeded Dominika Cibulkova of Slovakia also improved to 4-1 in head-to-head matches against the unseeded Spainiard Anabel Medina Garrigues after dispatching her 6-3, 7-6 (3) in 1 hour, 36 minutes at Ariake Coliseum.
In other first round matches, 14th-seeded Roberta Vinci of Italy beat Barbora Zahlavova Strycova of the Czech Republic 6-4, 4-6, 7-5 while Serbia's Jelena Jankovic overpowered Belgium's Yanina Wickmayer 6-3, 6-3.
Japanese wild card Ayumi Morita defeated Sorena Cirstea of Romania 6-2, 3-6, 6-2.
The $1.2 million tournament features 12 of the top 13 players in the world rankings.