Roddick defeated Paul Capdeville 3-6, 7-6 (2), 6-3, 6-3 Sunday, giving the United States an insurmountable 3-1 lead in its 4-1 victory over Chile in the first-round Davis Cup World Group series.
Roddick improved to 12-0 in matches that can clinch a Davis Cup matchup for the U.S. and is 33-11 overall in 24 series since 2001.
"It's always sweet, and every time you clinch one you think it's the sweetest," Roddick said. "I think it's also pretty satisfactory when everything is stacked against you -- you got the (clay) court, the crowd. It's a mental grind and you have to try and ignore everything."
Former Georgia Bulldog John Isner finished off the 4-1 victory with a 6-3, 6-7 (4), 7-5 win over Guillermo Rivera-Aranguiz in the meaningless second reverse singles. It was Isner's first win in four Davis Cup singles matches. He has two wins in doubles.
The victory was the first for new U.S. Davis Cup captain Jim Courier, who played on the 1992 and 1995 winning Davis Cup squads.
"I like the way all of our guys responded to adversity out there," he said. "John's match was a very important match for us as a team to have him go out there and battle through and have him win in singles."
The U.S. and Chile could have abandoned the fifth match under a new Davis Cup rule because the first reverse singles match went four sets, but Isner and Rivera-Aranguiz elected to play.
The Americans advanced to the quarterfinals and will play at home in July against Rafael Nadal and Spain, 4-1 winners over Belgium this weekend. Roddick's hometown of Austin, Texas, is being considered as the host, along with San Antonio and Albany, N.Y.
The U.S. team last played a home series in March 2009, beating Switzerland 4-1 in Birmingham, Ala.
"I think it's been no secret that I've wanted that (to play in Austin), so I certainly appreciate the effort put forward and hopefully we can get it," Roddick said. "It would be a dream come true to play at home a really cool experience.
"A guy named Rafa coming to town will provide a little bit of energy. It's as good a second round as I've ever seen. Any place will be good, as I'm just happy it will be on U.S. soil."
In the other first-round World Group series Sunday, defending champion Serbia handled India 4-1, Argentina closed out a 4-1 victory over Romania, Russia salvaged two matches in a 3-2 defeat to Sweden, Germany beat Croatia 3-2 when Philipp Petzschner outlasted Ivo Karlovic 6-4, 7-6 (3), 7-6 (5), France ousted Austria 3-2, and Kazakhstan upset the Czech Republic 3-2.