The Czechs had already secured a spot in the finals by taking a 3-0 lead over the first two days. On Sunday, Jan Hajek of the Czech Republic beat Roko Karanusic, 7-6 (4), 6-4 before Lovro Zovko gave Croatia its lone point with a 6-3, 6-4 win over Lukas Dlouhy.
The Czechs will face Spain away in December in the country's first Davis Cup final in 29 years.
For 2005 champion Croatia, it was only the second loss in 13 home matches in the Davis Cup.
6 hours, 78 aces: Czechs win Davis Cup marathonSrna’s agent rules out Barca
