Miki, Japan: Japan plucked victory from the jaws of defeat as the hosts beat Britain 3-2 on Sunday to seal a return to the Fed Cup's elite level after a four-year absence.
Johanna Konta crushed Naomi Osaka 6-3, 6-3 to put the visitors on the brink of victory before Kurumi Nara upset Heather Watson 7-6 (11-9), 6-4 to take a see-saw World Group II playoff tie to a deciding fifth rubber.
Konta and Watson looked to be cruising in the doubles before Miyu Kato and Makoto Ninomiya hit back to win 3-6, 6-3, 6-3, ending British hopes of breaking back into the Fed Cup's top 16 for the first time since 1993.
A missed Konta volley gave the Japanese breathing space in the final set before Ninomiya's crunching forehand on their third match point completed a fighting comeback win after two hours, 11 minutes.
"We were a bit tight in the first set but managed to get ourselves right from the second," said Kato, who had double reason to celebrate.
"It's my mum's birthday today so to win for Japan and for my mum is extra special."
Konta took just 75 minutes to beat Osaka, one of the rising stars of women's tennis who captured her first big title at Indian Wells last month.
The Briton, ranked one below Osaka at 23 in the world, sealed victory with a ferocious backhand down the line that took the air out of the home crowd.
"There was very little in it and it really could have gone either way," said Konta.
"I was happy I was able to stay tough when she was playing really well and raise my game when she dropped off a little bit."
But Nara's battling win over Watson set up a nervous finale and the British pair faded after a strong start as the visitors lost a promotion playoff for the fourth time in seven years.
"I've never seen support like this," said Japan captain Toshihisa Tsuchihashi.
"The players gave everything, but the crowd gave us a massive lift."