Misaki Doi thrashed Bibiane Schoofs 6-3, 6-2 on Sunday as Japan completed a 4-0 Dutch whitewash in a one-sided Fed Cup world group two relegation playoff.
The Netherlands, who just three years ago reached the Fed Cup semi-finals, slipped into the Europe/Africa group one after an abject display in Osaka.
Doi and Nao Hibino had put Japan firmly in control of the tie on Saturday, despite the absence of world number one Naomi Osaka.
World 104 Doi finished the job with a clinical performance against Schoofs, before Shuko Aoyama and Eri Hozumi added insult to injury for the Dutch by beating Lesley Kerkhove and Demi Schuurs 6-3, 3-6, 10-6 in the dead doubles rubber.
The final singles match was subsequently scratched.
“It took a while to find my rhythm but the crowd got behind me and gave me a lift,” said Doi after overpowering Schoofs with a barrage of backhand winners.
“To stay in the world group gives us something to aim for. It's a victory that gives hope to women’s tennis in Japan.”