MIKI, Japan - Japan held their nerve to beat Great Britain in the deciding doubles match in their Fed Cup World Group II Play-off and move through to next year's second tier.

Miyu Kato and Makoto Ninomiya came back from a set down in the final match to beat British pair Heather Watson and Johanna Konta 3-6, 6-3, 6-3 and secure a 3-2 victory in the tie.

With the tie level at 1-1 after Saturday's play, Konta had earlier eased past Indian Wells champion Naomi Osaka 6-3, 6-3 in the third rubber to give Britain a 2-1 advantage. Kurumi Nara brought the hosts level at the Bourbon Beans Dome, surviving three set-points to beat Watson 7-6, 6-4.

Watson and Konta were preferred in the final rubber to Anna Smith and debutant Gabi Taylor after Watson's defeat to Nara, captain Anne Keothavong making a late switch.

Watson secured the first set after a volley on Britain's second set-point, after Britain had won five successive games from 2-0 down. The visitors were unable to recover from a similar early score in set two, surrendering four break-point opportunities.

A 3-2 lead for Britain, after saving four break points themselves, was as good as it got for Watson and Konta in the final set of the fifth rubber, as some fine Japanese serving turned the match around and gave them momentum. 

Konta saved the first two match-points on her serve in the final game, but accurate returning earned a third match-point for Japan and they were not to be denied. Ninomiya struck the winning point and Japan prevailed after two hours, 11 minutes in front of a noisy crowd.

Britain's 25-year wait for a return to the World Group continues, Anne Keothavong's team falling at the final promotion hurdle for the fourth time in seven years. They now drop back down to the Europe/Africa Group next February, while Japan can ready themselves for an assault on the World Group II next year.

Elsewhere, World No.1 Simona Halep led her Romanian team into the World Group in 2019, becoming one of four nations to advance through the World Group Play-offs this weekend. Halep ousted former Top 10 player Patty Schnyder, 6-2, 6-1, to give the Romanians an insurmountable 3-0 lead in the tie and book their place in the top tier next year.

They will be joined by Belgium, who rolled past Italy 4-0 behind two wins by World No.17 Elise Mertens, and Australia, who won the final four matches of the weekend to get by the Netherlands, 4-1.

Belarus will claim the final spot in next year's World Group with the most dramatic World Group Play-off tie of the four. Last year's Fed Cup runners-up to the United States were pushed all the way to the decisive doubles match by the Slovakian team, but the Belarusians retained their spot in the elite group when Vera Lapko and Lidziya Marozava took down Viktoria Kuzmova and Anna Karolina Schmiedlova, 6-3, 6-4.

In the World Group II Play-offs, two teams with members of the WTA Top 5 joined Japan as winners. First, World No.3 Garbiñe Muguruza won both of her singles matches to push Spain past Paraguay, winning the third rubber over Veronica Cepede Royg by the scoreline of 7-6(2), 6-0. 

Then, World No.5 Jelena Ostapenko paired with World No.15 Anastasija Sevastova to win both of their reverse singles matches on Sunday, leading to Latvia's 3-2 triumph over the formidable four-time champions from Russia.

The final victor coming out of the World Group II Play-offs will be determined later on Sunday as Canada and Ukraine wrap up their tie in Montreal, which is currently deadlocked at 1-1.