Rafael Nadal got the winning point as Spain won a fifth Davis Cup title here on Sunday.
The World No. 2 beat Argentina's Juan Martin del Potro to give the host a 3-1 win, rallying from a set down to see off the 2009 US Open champion 1-6, 6-4, 6-1, 7-6 (0).
“It was an unbelievable match. These guys are great and that's why we were in the final,” said Spanish captain Albert Costa.
“Rafa tried to play deeper and harder because at the start Del Potro was inside the line and hitting so hard. He fought hard so that's why we won.”
Nadal and David Ferrer had won Friday's opening singles before David Nalbandian and Eduardo Schwank kept Argentina's hopes alive by beating Feliciano Lopez and Fernando Verdasco in Saturday's doubles.
Spain previously won the titles in 2000, 2004, 2008 and 2009.
But there was more heartbreak for Argentina which became the first nation to lose four finals — it also lost to Spain in the final three years ago at home.
Del Potro, who lost a marathon five setter to Ferrer on Friday, had gotten off to a strong start leading 6-1, 1-0 and 40-0 on his service against Nadal.
But Nadal hung on to get back into the match as Del Potro began to show signs of the fatigue from Friday's five-hour marathon playing with both of his thighs bandaged.
Despite looking dead and buried after losing his serve early in the fourth set, Del Potro managed to claw his way back into the tie with some magical shots which saw him serve for the set at 5-3.
Nadal dug deep however and the momentum swung his way again and once into the tie-break there was no looking back as he sealed victory after just over four hours on court.
It's the first time that Nadal had secured the winning point for his country and it came on the court where in 2004 he became the youngest Davis Cup winner aged 18.
The victory finishes a difficult six months for Nadal since winning Roland Garros in June.
“It was a very emotional match and I am happy for the team,” said Nadal.
“It was the most amazing atmosphere I have ever played in. The crowd were crazy. Everything was perfect.
“It was complicated at the start of the match, but the beginning of the second set was very important and at 1-0 and 40-0 that was the turning point for me.”
