on Saturday, and need just one more rubber to to claim the trophy.
Left-handed duo Feliciano Lopez and Fernando Verdasco won 5-7 7-5 7-6 (7/5) 6-3 which means the visitors, who started the tie as big underdogs with the injured Rafael Nadal missing from their line-up, need to win only one of Sunday's two singles rubbers to claim the trophy.
Argentina, who brought in David Nalbandian to play alongside Agustin Calleri following his singles win on Friday, drew first blood by taking the first set after Verdasco double-faulted to lose his serve in the 11th game.
But Spain hit back by taking the second, also 7-5, by breaking Nalbandian's delivery in the final game.
A thrilling third set followed and ultimately it was to prove decisive.
Spain seemed in full control with a 5-1 lead, but Argentina fought back much to the delight of the packed crowd in Mar del Plata.
The umpire struggled to keep the fans quiet with captain Alberto Mancini appealing for calm at one stage.
Spain managed to stop the rot to force a tie-break but in it Argentina moved 5-1 ahead only for more drama to unfold.
Suddenly Spain rattled off five points in a row to turn things around and take the 62-minute set for a two-sets-to-one lead.
Argentina looked crushed by the way that tie-break had unfolded and they were soon in big trouble in the fourth set.
Both Argentines lost their serve as Spain moved 5-2 ahead and although Nalbandian and Calleri got one of the breaks back, saving two match points in the process, Nalbandian was broken again as he served to keep the match alive.
Afterwards Lopez, who also won a singles rubber for Spain on Friday, warned his side were not home and hosed yet.
"We're ahead but there's a long way to go yet," he said.
"I wasn't expecting to win yesterday and today. Really being 2-1 ahead with one day to go is a dream."
Speaking about the doubles win, he added: "After Argentina recovered from being 1-5 behind in the third set, it was hard for me to come back to the match.
"But with some luck, we won the set."
Like Lopez, Spain captain Emilio Sanchez remains cautious ahead of Sunday's reverse singles.
He said: "We're ahead, we're only one point away from the victory. But there are no favourites here."
Sunday's singles matches are due to see Juan Martin Del Potro take on David Ferrer before Nalbandian meets Lopez.
However, the captains could yet make changes with Del Potro in particular struggling with injury.
Argentina team doctor Diego Rivas explained: "Del Potro underwent several tests and he doesn't have a muscular injury, only pain.
"We'll do everything possible to have him ready for Sunday."
Only five times in the competition's 108-year history has a side come from 2-1 down in the final to claim the cup, the last occasion being Russia's victory over France in 2002.
by http://www.espnstar.com/tennis/news
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