Ayumi Morita and Kimiko Date-Krumm both won in straight sets on Saturday as Japan took a 2-0 lead over Belgium in a Fed Cup World Group playoff.
Morita beat Alison Van Uytvanck 6-4, 6-4 in the first match and Date-Krumm overpowered Tamaryn Hendler 6-1, 6-4 in the second match at Ariake Colloseum.
Morita faces Hendler and Date-Krumm will take on Van Uytvanck in Sunday's reverse singles.
The winner of this weekend's tie will earn promotion to the elite eight-nation World Group in next year's Fed Cup, a level that Japan haven't competed at since 2007. The loser will be relegated to World Group II.