Rafael Nadal upset Andy Roddick 6-7 (6), 6-2, 7-6 (6), 6-2 and gave Spain a commanding 2-0 lead over the United States in the Davis Cup final on Friday.
In the first singles, Spanish No.
1 Carlos Moya beat Mardy Fish 6-4, 6-2, 6-3.
The sweep puts Spain on track to win its second Davis Cup, adding to the title won in 2000 over Australia in Barcelona.
The Americans have won the Davis Cup a record 31 times, but have not taken the team championship since 1995.
Only one team in Davis Cup history has come back from 2-0 down and won the final - Australia in 1939 in a win over the Americans.
In Saturday's doubles, American twins Bob and Mike Bryan face Nadal and Tommy Robredo, who can clinch the best-of-five series.
The Bryans, who are 4-0 in Davis play and have not lost a set, must win to keep the final alive into Sunday's reverse singles, where Moya was slated to face Roddick, and Fish against Nadal.
The 18-year-old Nadal was sensational on the slow, red clay on a chilly day at Olympic Stadium.
He combined power on his sweeping left-handed groundstrokes with touch on repeated drop shots that even Roddick applauded with his racket.
"I had cramps at one point but I got through it," Nadal said.
Asked if he was ready to play on Saturday, he replied: "Right now, I'm not.
I'm really beat.
But I think I'll be ready tomorrow.
" Officials said 27,200 tickets were sold, a record for a "sanctioned" tennis match.
The old mark was set in 1954 in Sydney, Australia, when 25,578 watched the United States defeat Australia in the Davis Cup final.
Roddick called the playing atmosphere "crazy.
" "It was unlike anything I have experienced before.
" And he gave all the credit to Nadal.
"I ran into someone who played too well," he said.
"Every once in a while people come along who are big match players.
He is a big match player.
You either have it or you don't.
" Despite dropping the first set in 71 minutes, Nadal came right back and swept through the second in 34 minutes, breaking Roddick twice.
In the 85-minute third set, Nadal failed to capitalize on any of eight break points and was again forced into a tiebreaker against the world No.2.
This time he won it, taking the set point on a backhanded, cross-court passing shot.
Nadal sprinted through the final set, winning over a dispirited Roddick.
Nadal dropped to his back after the winning point, and then rushed to the net to shake hands with Roddick.
It was only the second meeting between the two.
Three months ago in the second round of the U.S.
Open, Roddick won 6-0, 6-3, 6-4.
In the first match, a nervous Moya fell behind 3-0 in the first set, but came back and broke Fish twice to take the set in 40 minutes.
Moya broke Fish again to open second set, setting the tone as he swept through the match in straight sets in 1 hour, 57 minutes.
"At first the ball from Fish was bouncing higher than I expected, because of his power and topspin," Moya said.
"But once I got used to it I was able to handle his game.
"I was a little nervous at first, but now I hope Rafael can play with some confidence.
" The crowd was a blanket of red and yellow with a brass and drum section heating up the match.
Fans were wrapped in overcoats and some sat under umbrellas.
The court is undercover, but fringe areas are exposed to the open air.
"I tried everything," Fish said.
"I tried serving and volleying, I'd tried coming in on a lot of balls, I tried to stay back and he had answers.
I had some chances and he served a few of those chances away.
You have to tip your hat to him."