Spain set up a Davis Cup final against the United States after Rafael Nadal used his youthful exuberance to charge past France's Arnaud Clement on Sunday.
The teenager, drafted in to replace a below par Carlos Moya, skipped, jumped and punched the air after taking all the big points in a 6-4, 6-1, 6-2 victory, giving Spain an unbeatable 3-1 lead and a place in the final for the third time in five years.
"We're going to celebrate with champagne and cakes," said triumphant Spanish captain Jordi Arrese. "Then we'll start thinking about the final.
"The U.S. should be worried about us. They've got to come here and they'd better be prepared for clay."
The 2000 champions, runners-up to Australia last year, will have the advantage of choosing a clay surface when they host the Americans from December 3-5.
The U.S., champions a record 31 times, beat Belarus 4-0 in the other semi-final to reach their first final since 1997. The fifth and final rubber in Charleston, South Carolina between Mardy Fish and Andrei Karatchenia was abandoned due to rain.
"When I saw the draw early on, and I saw what the potential was, I was excited about going to Spain for the final," U.S. captain Patrick McEnroe said after his team took an unassailable 3-0 lead.
"It would be a tremendous challenge and a tremendous opportunity to do something amazing.
"We know they have a great team, and so do we. I think our guys will really get up for it."
Spain's Tommy Robredo beat Paul-Henri Mathieu 6-4, 6-4 to give his country a 4-1 win in Alicante and complete an excellent comeback after Moya's shock opening day defeat by Mathieu.
Nadal had carried Robredo to victory in Saturday's doubles against Clement and Michael Llodra and on the back of that performance was promoted for the first reverse singles.
"I was surprised when I found out on Saturday night that I'd be playing but also eager," said Nadal, who had previously played just two Davis Cup singles, winning one and losing one.
PRESERVED STATUS
Nadal grew in strength as the match wore on and over the last two sets Clement was simply overwhelmed by the left-hander's immense forehand.
While Spain and the U.S. look ahead to landing the biggest prize in men's team tennis, the champions from the last two years, Australia and Russia, preserved their World Group status by comprehensively winning their playoff ties.
They will be joined in the 16-team competition by Croatia, Chile, Czech Republic, Slovakia, Romania and Austria.
Olympic champions Nicolas Massu and Fernando Gonzalez guided Chile back into the World Group for the first time in 20 years when they beat unheralded Japanese pair Takao Suzuki and Thomas Shimada in the doubles.
Canada and Morocco were both relegated to the second tier after suffering 4-1 defeats by Romania and Australia respectively.
Former winners Germany and Britain failed in their bids to get promoted. Both countries went into the deciding ties deadlocked at 2-2 but were easily outclassed in the final rubbers.
Slovakia's Karol Kucera hammered Florian Mayer 6-4, 6-0, 6-2 in Bratislava while Stefan Koubek ran out a 7-6, 6-4, 7-5 win over a tired Greg Rusedski in their rain-interrupted tie in Portschach.
Chile whitewashed Japan 5-0 in Santiago while the Czech Republic hammered Paraguay by the same score in Asuncion.