The scores of the near 6-hour match, 6-7 (5-7), 7-6 (7-5), 7-6 (8-6), 6-7 (2-7), 16-14, put the Czechs within one victory of advancing to the Davis Cup finals.
The fourth-longest match in Davis Cup history featured a record 78 aces by the 6-foot-10 Karlovic, a 30-game marathon fifth set and just one service break.
Also, the 82 games played equaled the record for the most number of games played in a single match since the tie-break was introduced to Davis Cup competition in 1989.
"The crowd was amazing," Stepanek said. "It was like playing at home. I was very surprised. The Croatian fans were great as well. They gave the players lots of support and huge atmosphere."
In the later match, Tomas Berdych beat Marin Cilic 6-3, 6-3, 3-6, 4-6, 6-3.
Copyright 2009 by United Press International.