Croatia reached the Davis Cup semi-finals for the first time on Sunday after Ivan Ljubicic beat Romania's Andrei Pavel in the first reverse singles in Split.
Croatia, who defeated the United States in the opening round, now take on 2002 champions Russia in September.
"This was one of my best feelings on a tennis court," said Ljubicic. "The spectators were great, I had goose bumps for the whole of the third set."
A break in the sixth game was enough for Ljubicic to secure the opening set. Pavel broke early in the second but the Croat reeled off five consecutive games to take command of the match.
"I was mad at myself losing the serve in the second set," said Ljubicic. "It was all me, and my mistakes, but once I got back on track I knew I had to win this match in three sets."
Mario Ancic completed a 4-1 victory with a 7-6 7-6 win over Victor Hanescu in the dead rubber.