Former World No.1 Caroline Wozniacki was pushed hard by Serbian qualifier Bojana Jovanovski in the first round of the Japan Open Monday, winning the match in a tense decider.
Wozniacki wrapped up the rain-interrupted match 6-0, 3-6, 6-4 and will now play either Russia's Ekaterina Makarova or Slovakia's Daniela Hantuchova, who are both unseeded.
Wozniacki was playing the day after winning the Korea Open in Seoul, where she beat Kaia Kanepi 6-1, 6-0 in the final.
Earlier, World No.78 Heather Watson made up 48 ranking places to upset Sabine Lisicki 6-4, 7-6(3) on the hard court in Tokyo and set up a meeting with world No.2 Maria Sharapova, whose status as second seed meant she received a first-round bye.
Watson's win prevents a rematch between Sharapova and Lisicki, who have clashed memorably at Wimbledon on three occasions, the Russian winning last year's semi-final and beating Lisicki at the Olympics in August, but losing to the German in the fourth round at SW19 this year.
Elsewhere, World No.10 Marion Bartoli secured her place in the second round by beating local hero Kimiko Date-Krumm in straight sets.
France's Bartoli, seeded ninth in Tokyo, beat the 41-year-old veteran Date-Krumm 6-1, 6-4.
Bartoli's opponent in the second round will be German 17th seed Julia Goerges, who beat her Romanian first-round opponent Monica Niculescu 6-3, 6-2.
Former world No.1 Ana Ivanovic was leading 6-3, 2-0 when her Czech opponent Andrea Hlavackova retired. She will now play Urszula Radwanska.
Former French open champion Francesca Schiavone knocked out Kazakhstan's Yaroslava Shvedova 6-4, 7-6(4), 6-4. The Italian's reward is a second-round match with eighth seed Sam Stosur.
Russian No.6 Anastasia Pavlyuchenkova beat South Africa's Chanelle Scheepers, winning a tight match 6-4, 4-6, 7-5, and will now face seventh seed Li Na.