Tommy Robredo was the driving force as Spain came from behind to beat Britain 2-1 on Saturday to win the Hopman Cup for a third time.
Fifteen-year-old Laura Robson stunned world number 26 Maria Jose Martinez Sanchez 6-1, 7-6 to give Britain a surprise lead but Robredo upset world number four Andy Murray 1-6, 6-4, 6-3 to leave the tie all square heading into the mixed doubles.
The Spaniards then saved three set points in the opening set of a dramatic match before going on to clinch the title with a 7-6, 7-5 victory.
Martinez Sanchez described Robredo as "the hero" but the modest world number 16 said it was a team effort.
"It was a great final," he said.
"Maria Jose said today I did a great job but here no one wins alone."
For Robredo, it was his second Hopman Cup victory after partnering Arantxa Sanchez Vicario to the title in 2002, and the pair each took home a special diamond-encrusted tennis ball as a trophy.
Former junior Wimbledon champion Robson was not given much chance against Martinez Sanchez, ranked 377 places above her, but she produced an outstanding display to make a mockery of the huge rankings gulf.
A brilliant drive volley gave her the first break in the fourth game and she then broke again two games later on the way to winning the first set.
Martinez Sanchez slowly worked her way into the match and broke to lead 5-3 but Robson broke back and then saved a set point at 4-5 as the pair headed to a tiebreak.
Robson won six straight points to lead 6-2 but the Spaniard hit back to 6-6 only for Robson to smash two groundstroke winners to seal the best win of her young career.
"From 6-3 she started going for her shots but then at 6-6 I was like, 'OK, just go for your shots'," Robson said. "I am really happy."
Murray looked on course for an easy win when he blitzed world number 16 Robredo in the first set with more of the huge hitting he had displayed all week.
But Robredo refused to buckle and as Murray's form dipped, the Spaniard broke serve in the 10th game to take the second set.
One break, in the second game, put Robredo ahead in the decider and he held his nerve to clinch a morale-boosting win.
Murray lifted himself again for another effort in the mixed doubles but Britain missed their chance in the first set as they let slip a 6-3 lead in the tiebreak to lose it 8-6.
Robson played superbly to keep Britain in the second set and the Britons saved two Championship points at 5-4 but Robredo slammed a backhand down the line two games later to seal victory.
The teenager's productive week was given a further boost on Saturday when she was awarded a wild card for the Australian Open qualifiers.