The United States swept past Belarus on Saturday to clinch their first Davis Cup final appearance since 1997.
Twins Bob and Mike Bryan defeated Belarus's Max Mirnyi and Vladimir Voltchkov to give the Americans an unassailable 3-0 lead in the semi-final tie in Charleston.
The Bryans, who are unbeaten in Davis Cup matches, won 6-1, 6-3, 7-5 to finish off Belarus after world number two Andy Roddick and Mardy Fish had won their singles matches on Friday.
The Americans will face 2000 champions Spain or France in the final, with Spain looking favourites after Tommy Robredo and Rafael Nadal claimed a tense doubles victory to give them a 2-1 lead going into Sunday's singles.
Trailing 1-0 after Frenchman Paul-Henri Mathieu had upset Carlos Moya on Friday, Spain finally made home advantage count by grabbing both points on Saturday.
Juan Carlos Ferrero completed a 6-3, 6-1, 1-6, 6-3 win over an injured Fabrice Santoro in a match held over due to bad light before Robredo and Nadal edged past France's Arnaud Clement and Michael Llodra 7-6, 4-6, 6-2, 2-6, 6-3.
Santoro finished the match with a painful wrist injury, leaving French captain Guy Forget to draft in Clement as a replacement in the doubles.
"I woke up this morning and could barely hold a racket... it was warm so I could play on. But you can't beat a great player like Juan Carlos when you're injured," said Santoro.
France's new-look doubles pairing had plenty of chances but the Spaniards prevailed in five error-strewn sets lasting three hours 47 minutes at Alicante's Plaza de Toros.
BIG STEP
"We've taken a big step towards the final with this win," said Spanish captain Jordi Arrese.
Australia preserved their World Group status when Wayne Arthurs and Todd Woodbridge recorded a 7-6, 7-6, 6-3 victory over Moroccans Mounir El Aarej and Mehdi Tahiri for an unbeatable 3-0 lead in their playoff tie.
Croatia and 2002 champions Russia also secured their places among the 16 nations who will battle it out for the Davis Cup next season after taking winning 3-0 leads.
Romania and Germany will carry 2-1 advantages into the final day of their ties, while Britain and Austria were locked at 1-1 after bad light forced an early halt to their doubles encounter.
In Moscow, a rejuvenated Marat Safin vowed to help Russia win back the Davis Cup next year after teaming up with Mikhail Youzhny for a 6-2, 6-1, 6-4 win over Thai twins Sanchai and Sonchat Ratiwatana.
Humbled by Belarus in the first round this year, Safin believes Russia can get back to the top.
"We have a new, young team, which is capable of doing great things in the near future," said the former U.S. Open champion.
"(Igor) Andreev is turning into a top-class player, Youzhny is still young and capable of repeating his Davis Cup heroics and myself -- we have a core of a pretty good team here."
In Asuncion, Jiri Novak and Radek Stepanek gave the Czech Republic a winning 3-0 lead over Paraguay while Fernando Gonzalez and Nicolas Massu earned Chile an unbeatable 3-0 cushion over Japan in Santiago.
