World number two Daniil Medvedev beat Marin Cilic to lead the Russian Tennis Federation to a third Davis Cup title.
Andrey Rublev had won the first singles match against Borna Gojo 6-4 7-6 (7-5) to put the Russians ahead in Madrid.
Medvedev did not drop a set at the tournament in a year where he won his maiden Grand Slam title at the US Open.
The Russians are the fourth nation to win both the Davis Cup and Billie Jean King Cup - the women's equivalent team competition - in the same year.
Medvedev was initially tested in the first set by 2014 US Open champion Cilic, who was part of the winning Croatian team in 2018.