David Ferrer also claimed a valuable win against Del Potro whilst Spain's doubles pair of Feliciano Lopez and Fernando Verdasco suffered defeat at the hands of Argentina's David Nalbandian and Eduardo Schwank.
The win signalled Spain's fifth success in the competition and their third in the last four seasons. Nadal has been a pivotal figure in Spain's recent triumphs, this year claiming his 15th and 16th consecutive wins respectively.
Nadal was in spectacular form, comfortably defeating Monaco in three quick sets on the opening day of the series, winning 6-1 6-1 6-2. The world number 26 was just no match for the aggressive and powerful forehands of Nadal.
Ferrer, on the other hand, was made to fight for his victory and eventually managed to overcome Del Potro after a thrilling five-set encounter that lasted nearly five hours. World number five Ferrer was ecstatic with his performance over the number 11 seed, eventually settling the tie 6-2 6-7 (2-7) 3-6 6-4 6-3. He said: "I played maybe the best match of my career, I am very happy.
Argentina kept their hopes alive, however, on the second day of play when their doubles pair ran out convincing winners. Despite the best efforts of the Spanish crowd to urge their countrymen to victory, the Argentinian duo produced a resolute team display to win the match 6-4 6-2 6-3. But Albert Costa, captain of the Spanish side, remained optimistic about his country's chances, particularly after the impressive opening day displays by Nadal and Ferrer. "I have Rafa and David and we're going to win one of those two points."
His faith was justified on the final day when Nadal overcame Del Potro 1-6 6-4 6-1 7-6 (7-0) sparking emotional scenes from the Spanish contingent and leaving the Argentines devastated and still in search of a first Davis Cup title. Nadal was completely out-of-character in the first set, seeing his service overpowered time and time again. However, he seemed to spark into life in the second set, his unstoppable forehand once again proving key. He dominated the third set before a brave effort from Del Potro in the fourth resulted in a tie-break success for the Spaniard and another trophy to add to a blossoming collection.
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