British number one and eighth seed Laura Robson saw off Greece's Eleni Daniilidou 6-4 6-2 to reach the second round of the HP Open in Osaka.
Robson, seeded in a WTA tournament for the first time, appeared to be letting her opponent back into the match when Daniilidou came back from 3-0 down in the second set to the brink of levelling at 3-3.
But Robson held a tough service game, re-established her double break at 5-2 and served out at the first attempt to join compatriot Heather Watson in the second round, where she will face either Japan's Kurumi Nara or Zhou Yimiao of China.
British number two Watson, who won her first-round singles match on Monday, also made it through to the second round of the women's doubles.
The 20-year-old and her 42-year-old Japanese partner Kimiko Date-Krumm, who are the fourth seeds, beat Canada's Eugenie Bouchard and American Alexa Glatch 6-3 6-2.