World number two Daniil Medvedev celebrated the "best weeks" of his career as he led the Russian Tennis Federation to a third Davis Cup title.
Medvedev's 7-6 (9-7) 6-2 win over Marin Cilic sealed a 2-0 victory over 2018 champions Croatia in the Madrid final.
Andrey Rublev had won the first singles match against Borna Gojo 6-4 7-6 (7-5).
"It feels amazing but I am more happy for the team than for myself," said 25-year-old Medvedev, who did not drop a set at the Finals.
"It is never easy to come at the end of the season but it was the best two weeks of my career."
The Davis Cup triumph comes at the end of a season in which Medvedev 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.