Rafa Nadal thrashed Juan Monaco and David Ferrer rallied to fell Juan Martin Del Potro in five thrilling sets to give Spain a 2-0 lead over Argentina in the Davis Cup final on Friday that put the favourites on the brink of a fifth title.

Playing on his beloved clay before a rowdy crowd at the Olympic Stadium, Nadal got Spain's bid for a third trophy in four years off to a predictably solid start with a 6-1, 6-1, 6-2 destruction of 26th-ranked Monaco, the World No. 2's training partner.

As night fell over the Andalucian capital, the tenacious Ferrer fought back from two sets to one down to beat Del Potro 6-2, 6-7, 3-6, 6-4, 6-3 after almost five hours of attritional tennis and send the red and yellow clad home support into raptures.

"That was the match that we wanted from our side," Argentina captain Tito Vazquez said. "We were very close but not close enough. It's very difficult.

"For us we have to start thinking about tomorrow, about winning the doubles, and then who knows.

"Maybe Del Potro recovers, he is capable of beating Nadal. You never know, we could be back in the game but it's a difficult task."

Needing to win Saturday's doubles and Sunday's two reverse singles in the best-of-five tie, Argentina face a seemingly impossible task to secure a first Davis Cup trophy in their fourth final with Nadal apparently unbeatable on the red dust.

The muscular Mallorcan clubbed 27 winners on the specially constructed indoor court, which straddles the running track at one end of the arena, 20 of them on his fearsome forehand.

Monaco looked powerless as he was dismissed with brutal ease on an unusually damp afternoon in Seville.

Showing no sign of end-of-season fatigue, Nadal took his Davis Cup singles record on clay to 15-0 as Spain sought to add to their four titles against an Argentina team they upset to win the trophy in Mar del Plata in 2008.

After winning just two games in the opening two sets, Monaco made a better fist of the third.

Nadal, though, seemed to crush his spirit in the fifth game after an incredible rally that had both players scrambling all over the court and brought the 73-year-old King Juan Carlos of Spain to his feet.

The point, which left Monaco with a bloodied left knee and a bruised wrist, secured Nadal his sixth break of serve and he broke again for a 5-2 lead before serving out the match to love.

Nadal said he tried to lift Monaco's spirits in the dressing room after the match.

"He hasn't played that bad as to get that result but it's just I have made very few mistakes," the 10-times grand slam champion said.

"He's one of my best friends and I was in the locker room talking with him. He knew it was because I played especially well and not because he played especially bad."

Monaco was realistic about playing a man who has only lost one five-set match on clay in his professional career, to Robin Soderling at the 2009 French Open.

"I'm very sad because nobody likes to lose this way," the Argentine said. "But I am also aware that in front of me I had one of the best tennis players in history."

Ferrer came close to losing his unbeaten record in Davis Cup singles matches on clay, but clawed his way back against the big-hitting but erratic Del Potro to extend his winning run to 12 on the surface.

The World No. 5 stuttered when he was broken serving for the match at 5-1 up in the decider but secured victory at the second attempt two games later with a crashing forward winner that caught the baseline.

"I don't have a serve of 200 kilometers an hour and I don't have a volley like (Roger) Federer but I'm in shape," Ferrer said. "I had to be almost perfect otherwise I wouldn't have won."

Spanish pair Feliciano Lopez and Fernando Verdasco will take on David Nalbandian and Eduardo Schwank in Saturday's doubles.