Argentina, having qualified in thrilling fashion for their third Davis Cup summit clash by avenging their 2006 final defeat by Russia in Buenos Aires on Sunday, must decide how to make best use of home advantage when they play off for the trophy in November against Spain, who eliminated the holders United States in the other weekend semi-final. Juan Martin del Potro, who clinched Argentina's 3-2 victory over Russia by thrashing Igor Andreev 6-4, 6-2, 6-1 in the deciding rubber, developed his precocious skills on the red clay of South America. So did the more experienced David Nalbandian, who helped him overcome the powerful Russians. The snag is that clay is the domain of Rafael Nadal, the new world No 1, who has proved in winning four successive French Opens and a host of other titles that he is unrivalled on the surface. Nadal and his teammates, including the world No 5 David Ferrer, would be delighted if they were invited to a clay court showdown, but the Argentines know their plan to capture the elusive crown at the third time of asking has a better chance of succeeding in conditions that suit them most. The exciting emergence of del Potro as a major force in the world game may change that line of thinking, though. He won two tournaments on the American hard courts during a stunning run of 23 straight victories which was ended by Britain's Andy Murray in the quarter-finals of the US Open. He would surely fancy his chances of beating whoever Spain nominate as their No 2 player - it was Ferrer who beat Andy Roddick in an epic five-setter in the semi-finals - on a faster surface. If he can persuade his colleague David Nalbandian, a former runner-up on the grass of Wimbledon, to forsake his beloved clay for the good of the nation then Argentina could be on to a winner. They will be budgeting for two defeats by Nadal, who has demonstrated his growing versatility by winning Wimbledon this year, but if they can match that with two victories over Ferrer, or any of three other Spaniards in the world's top 20, then the destination of the Cup, first played for in 1900, could be determined by the doubles rubber. Del Potro will not be thinking too much about the Nov 21-23 final today as he celebrates his 20th birthday as Argentina's new national hero following his excellent demolition work against the Russians. After he and Nalbandian had taken both of the first day singles, the Russians won the doubles and drew level after Nikolay Davydenko overcame a tiring Nalbandian in the reverse singles, leaving del Potro and Andreev to fight it out for glory. It proved a one-sided fight as del Potro followed up his emphatic straight-sets victory over Davydenko with another resounding triumph to be mobbed by his overjoyed colleagues. Alberto Mancini, the Argentina captain, said: "He [del Potro] played incredible tennis. He began nervously, which is logical, but after that he showed his real self."