The French had clinched the best-of-five series even before Sunday's reverse singles and Benneteau's 6-2, 7-5 win over Benjamin Becker made the final score 4-1.
Earlier, Frenchman Jo-Wilfried Tsonga retired from his match when he was injured in a fall. That gave German Simon Greul a 4-6, 6-2, 1-0 victory and marked the first Davis Cup loss for Tsonga.
Gael Monfils and Tsonga put the French in control with singles victories Friday and Benneteau and Michael Llodra teamed for a four-set doubles win Saturday that sealed the best-of-five series for France.
Sunday's singles, since they had no effect on the series outcome, were shortened to three-set matches.
France draws two-time defending champion Spain in July in the Davis Cup quarterfinals. Spain got past Switzerland 4-1 in its first-round series.