The Italians held off a determined comeback effort by the American pair to win 6-4, 7-6, 5-7, 2-6, 6-3. Victory leaves Italy seeking their second Davis Cup title and first since 1976 when they host the defending champions, Sweden, in the final on 4 December.
The United States had won their last 18 home ties, but with leading players refusing to appear in the semi-finals they fell behind after Friday's singles, when Gaudenzi beat the Davis Cup debutant, Jan-Michael Gambill, and Davide Sanguinetti defeated Martin.
Sweden overcame Spain 4-1 to advance to their fourth final in five years. Jonas Bjorkman beat Carlos Moya 6-3, 7-5 yesterday for his third victory of the weekend. But he may only get doubles duty if the Italians now decide that the finals will be played on a clay surface.
"I think they'll choose clay and that means it will be difficult for me to get a singles spot," Bjorkman said. "It might be that the clay-court guys have to step in and play the final."
Clay is Bjorkman's weakest surface. Even though indoor clay is generally faster than the outdoor variety, the Swedish captain, Carl-Axel Hageskog, will probably rely on his three Magnuses - Gustafsson, Norman and Larsson - for the singles matches if the Italians choose the slower surface.
Gustafsson clinched Sweden's first-round victory on clay away against Slovakia after the defending champions fell behind 2-0 on the opening day.
Sweden is the most successful recent Davis Cup nation with six wins and five runners-up finishes since 1975, when Bjorn Borg captained the team.Reuse content