MAR DEL PLATA, ARGENTINA: FELICIANO LOPEZ, who had been handed the unenviable task of replacing injured world No.1 Rafael Nadal, stormed to Spain's rescue on Friday when he levelled the Davis Cup final against Argentina.

The stylish left-hander defeated Argentine No.1 Juan Martin del Potro 4-6, 7-6 (7-2), 7-6 (7-4), 6-3 to make the score 1-1 after David Nalbandian had put the home side ahead with an easy 6-3, 6-2, 6-3 win over David Ferrer in the opening singles rubber.

Lopez was unfazed by a passionate 11,000-strong home crowd at the Estadio Islas Malvinas and saw off the 1.98-metre giant del Potro, the world No.9, who ended the match with a crippling groin injury which could rule him out of Sunday's reverse singles.

Del Potro, who had secured Argentina's final place with a fifth-rubber win over Igor Andreev in September's semi-final against Russia, had cruised through the first set with a break in the fifth game.

But Lopez, seven years the Argentine's senior, then took two nerve-tingling tie-breaks, defying the wild support of the local crowd who were repeatedly warned by the umpire to curb their enthusiasm.

Del Potro hurt his groin when he went 4-2 down in the fourth set and he never recovered, with Lopez taking the match after three hours, 20 minutes when the home player netted a comfortable forehand.

"Emotionally, that was the best win of my career," said Lopez. "I played a bad first set but then I was more focused and I was the better player. I found a way to play my best."

Nalbandian had little trouble seeing off the highly strung Ferrer to give Argentina a boost in their bid to win a first Davis Cup title.

"I played a very good match - I was very solid from the first point and I was playing at a very high level," said Nalbandian, who will play alongside Agustin Calleri against Lopez and Fernando Verdasco in the doubles.