Fribourg - Roger Federer's miserable return to Davis Cup first-round duty after an eight-year absence was completed on Saturday when the United States knocked out Switzerland to reach the quarter-finals.
Having lost his first singles match in the tournament in nine years when he was defeated by John Isner on Friday, Federer teamed up with Olympic Games gold medal-winning partner Stanislas Wawrinka in the crucial doubles.
But Mike Bryan and Mardy Fish held their nerve after losing the first set to complete a 4-6, 6-3, 6-3, 6-3 win to romp to an unassailable 3-0 lead.
On Friday, Federer's 15-match winning streak in the competition came to an end when he slumped to a shock 4-6, 6-3, 7-6 (7/4), 6-2 loss to Isner, while Fish defeated Wawrinka 6-2, 4-6, 4-6, 6-1, 9-7.
"It was a tight match. Maybe our level dropped a tiny bit, just a game in each set made the difference," said Federer, who insisted he will remain committed to the tournament.
"I enjoy being with the guys. We will take it tie by tie. It's not a setback, or a step forward, it's nothing like that. I enjoy my time with the team and with (captain) Severin (Luthi). That's what counts for me."
The United States, who have won the Davis Cup a record 32 times, will now tackle either France or Canada, who were 1-1 after the opening day in Vancouver, in April's quarter-finals.
"It feels great to win. I know what it's like to lose and that's not good," said Fish. "You always want to play with Mike, he's one of the best doubles players ever."
Mike Bryan and Fish were teamed together when Bob Bryan skipped the tie to be with his new-born daughter.
"It's fun to play with Mardy, he's a clutch player to come back after a four-hour singles on Friday and back it up. It's unbelievable," said Mike Bryan.
Meanwhile, defending champions Spain reached the last eight for a sixth successive year when they secured an insurmountable 3-0 lead over Kazakhstan in Oviedo.
Marcel Granollers and Marc Lopez defeated Evgeny Korolev and Yuriy Schukin 6-2, 6-3, 6-1 to put Spain - playing without Rafael Nadal - into a last-eight clash against either Austria or Russia.
In Friday's opening singles, Juan Carlos Ferrero had beaten Mikhail Kukushkin 6-1, 4-6, 7-6 (7/2), 4-6, 6-4, while Nicolas Almagro saw off Andrey Golubev 6-3, 4-6, 6-1, 6-1.
"I learned a lot of things, especially that we have a lot of players to choose (from), lots of players that are capable and ready to play," said Spain captain Alex Corretja, in charge for the first time.
Russia stayed alive against Austria in Wiener Neustadt when Nikolay Davydenko and Mikhail Youzhny clinched a 7-6 (7/1), 6-7 (7/9), 7-5, 3-6, 6-4 win over Alexander Peya and Olivier Marach to stand at 2-1 down ahead of Sunday's reverse singles.
The Czech Republic made the quarter-finals when Tomas Berdych and Radek Stepanek eased past Daniele Bracciali and Potito Starace 6-3, 6-4, 6-2 for a 3-0 lead over Italy in Ostrava.
In April's quarter-finals, they will tackle either Serbia or Sweden.
Serbia, the 2010 champions, who are without world No 1 Novak Djokovic, led 2-0 after Friday's singles, but were pegged back on Saturday when Johan Brunstrom and Robert Lindstedt clinched the doubles.
They claimed a 3-6, 6-3, 7-6 (7/4), 6-7 (3/7), 10-8 win over Janko Tipsarevic and Nenad Zimonjic.
Ivo Karlovic teamed up with Ivan Dodig to win the doubles as 2005 champions Croatia took a 2-1 lead over Japan in Hyogo.
The country's No 3 and 4 coasted to a 6-4, 6-4, 3-6, 6-3 victory over Tatsuma Ito and Yuichi Sugita.
The winners of the tie will face 2011 runners-up Argentina, who completed a 3-0 win over Germany in Bamberg when David Nalbandian and Eduardo Schwank defeated Tommy Haas and Philipp Petzschner 3-6, 4-6, 6-4, 6-3, 6-4.