Roddick never faced a break point against Mathieu
Andy Roddick guided champions United States to the Davis Cup semi-finals by winning Sunday's reverse singles against France's Paul-Henri Mathieu.
Roddick served strongly to win 6-2 6-3 6-2 - his second singles win in the tie - and give the US an unbeatable 3-1 lead in the tie in North Carolina.
The holders will now face Spain, who had already secured victory over Germany on Saturday.
The other semi-final will pit Russia against Argentina.
Roddick was in superb form against Mathieu, breaking his opponent five times.
The Frenchman double-faulted to give Roddick the first set and was then broken again in the second games of the second and third sets.
Roddick sealed the win with an ace down the middle before doing a lap of honour around the court with his team-mates and the American flag.
Russia advanced after Tomas Berdych of the Czech Republic withdrew injured from his match with Nikolay Davydenko.
Berdych fell and hurt his ankle when he lunged for a forehand in the fifth set, giving Davydenko a 6-3 2-6 6-7 6-3 1-2 win and Russia a winning 3-1 lead.
Russia's win was the second time in a row they had advanced after an opponent retired with an injury in a decisive match.
Serbia's Novak Djokovic pulled out while leading Davydenko in the opening reverse singles match in the first round in February.
In the final singles of the quarter-final in Moscow, Lukas Dlouhy beat Marat Safin 6-3 6-3 to make the final score 3-2.
In Buenos Aires, David Nalbandian recovered from two sets to one down to beat Robin Soderling 6-4 1-6 4-6 6-4 9-7 in a match lasting four hours and nine minutes.
The 26-year-old, who has never lost a Davis Cup rubber at home, also beat Thomas Johansson in Friday's opening rubber and partnered Guillermo Canas in Saturday's doubles win.
Against Soderling, Nalbandian broke serve in the opening game and then held to go 2-0 up and his better shot placement allowed him to take the set.
Soderling then got two successive breaks in the second set and converted his fourth set point before also breaking twice in the third set as the wind picked up.
Nalbandian was broken in the first game of the fourth set but recovered to break back in the fourth and eighth games to send the match to a fifth set.
Although Soderling got the early advantage in the decider, breaking in the third game, Nalbandian immediately broke back and then Soderling had to save three match points to hold service to 5-5.
But Nalbandian kept cool, breaking again in the 16th game to seal the win.