World No. 5 David Ferrer put the defending champion Spaniards ahead with a 6-3, 6-4, 6-4 decision over Radek Stepanek before Berdych, ranked No. 6, held off Nicolas Almagro for a 6-3, 3-6, 6-3, 6-7 (5-7), 6-3 win.
The match took 3 hours, 58 minutes, ending just before midnight in Prague. That gives Berdych about 14 hours to recover before Saturday's doubles.
Berdych and Stepanek, 3-0 in Davis Cup doubles this year, are assumed to be the team for the Czechs in doubles. Spain is sending out Marcel Granollers and Marc Lopez, who are 1-2 in Davis Cup in 2012 and are coming off a win at the World Tour Championships in London.
Berdych, 9-0 overall in Davis Cup this year, just got by Almagro in a well-played tense match. There were five breaks as servers controlled play through the first four sets, but Berdych took a 4-2 lead with the first break of the fifth set.
However, Almagro broke back immediately only to have Berdych come up with break No. 5. Berdych then served out for the win.
Earlier Friday, Ferrer dropped serve just twice, winning two-thirds of the points on serve. He also took nearly half of the points off Stepanek's serve.
Friday's split means the Sunday's reverse singles will decide the 100th Davis Cup title. Berdych and Ferrer are to meet in the first match with Almagro and Stepanek going in the other.