Marin Cilic beat France's Lucas Pouille in straight sets on Sunday to give Croatia an unassailable lead in the Davis Cup final.
Cilic won 7-6 (7/3) 6-3 6-3, to dethrone defending champions France and secure Croatia's second Davis Cup, 13 years after their first.
Pouille took Cilic to a tie-break in the first set but could not mount a challenge in the next two, losing in two hours, 19 minutes.
Croatia won all three singles matches in straight sets.
"It's just a dream weekend, we all dreamed of playing as well all weekend," said Cilic.
"We did not even concede a service (in singles)."
It was the last final in the traditional format before a radical reorganisation of the venerable competition.
"Yes, that makes it special," said Cilic.
The victory gives Croatia some revenge for their football team's defeat by France in the World Cup final in July.
"We can't wait to be in Zagreb, like the footballers when they came back from the World Cup," said Zeljko Krajan, the Croatia captain.
In the 2016 final, Cilic also played the first reverse singles with Croatia a point ahead, but lost in five sets to Juan Martin del Potro and Argentina went on to win 3-2.
"We were in this position before and Marin did not manage to do it," said Krajan.
"This time, I told them they were strong enough and that they would only have to focus on their game for this to happen.
-PTI