Great Britain lost their Davis Cup tie against Serbia & Montenegro when Greg Rusedski fell to a 3-6 6-4 3-6 6-7 defeat to 18-year-old Novak Djokovic.
Rusedski was playing his third match in three days
Rusedski, who had to win to keep the Euro-Africa Zone tie alive, saw the first set slip away following three successive double faults in game eight.
Rusedski won set two, but Djokovic's passing ability proved the difference.
Arvind Parmar beat Ilia Bozoljac 7-5 6-4 in the final singles to make the overall score 3-2 to the visitors.
The defeat leaves Great Britain facing a Euro-Africa Zone relegation play-off against Israel in July.
Rusedski made 14 double faults in total, including one on match point, but GB captain Jeremy Bates insisted the focus should be on Djokovic.
"I don't think his service was the cause of the defeat today," Bates told BBC Sport. "Djokovic was outstanding.
"Greg had played a lot of tennis and he needed to shorten the match and the points.
"I thought Greg played an outstanding match but all credit to Djokovic - he was passing repeatedly through the narrowest of gaps and retrieved some shots that were superhuman."