Laura Robson broke down in tears after a battling performance against Sofia Arvidsson was not enough to prevent Sweden's victory over Great Britain in the Fed Cup.
She needed to win to keep alive any hopes of sealing a place in World Group II but went down 6-4 1-6 6-3.
Anne Keothavong was also beaten but Elena Baltacha and Heather Watson combined well to prevent the whitewash.
The 4-1 defeat means Britain go back into Euro/Africa Zone Group I.
Robson was making her singles debut in the competition.
"I'm pretty upset but my team-mates are proud of me," said the 18-year-old.
"Maybe in a few days I'll think it was a pretty good effort but right now I'm devastated.
"I had incredible support from the side of the court. I tried to be aggressive and stick to the gameplan.
"In Fed Cup you're not just playing for yourself, you're playing for your country, and all the emotion that built up on court just came through."
The teenager was a late replacement for Elena Baltacha, who struggled for fitness during her straight-sets loss to Johanna Larsson on Saturday.
Initially, it looked as though the power of Arvidsson was going to be too much for Robson as the Sweden number one climbed into a 4-0 lead.
However, Robson showed plenty of fight and clawed back to 5-4 before Arvidsson won the next game to take the first set.
But the fightback clearly filled Robson with confidence and, after the pair remained on serve for the first three games, she broke to move into a 3-1 lead.
That rattled Arvidsson and Robson took advantage, winning the next three games to take the set 6-1 and set up a decider.
Robson found herself 5-3 down in the third set but still she refused to give in, saving eight match points before Arvidsson took it on the ninth to finally seal victory for Sweden.
Keothavong played the first of the dead rubbers and went down 6-7 (8-6) 6-3 4-6 to Johanna Larsson.
With Britain facing a potential whitewash Baltacha joined forces with Heather Watson, who was featuring for the first time in Boras.
They put in an excellent performance to beat Ellen Allgurin and Hilda Melander 7-6 (7-3) 6-1.
Speaking after the tie, team captain Judy Murray said: "There is a lot to be excited about with some very positive performances from the team today and we managed to get a win in the doubles, which was a great way to finish.
"We're very, very proud of Laura. She left nothing on the court and there was so little in it.
"It's back now to the 15-team division, so we just need to go back there and do it all again and if we get the chance again next year we will be prepared and ready."