Tomas Berdych and Jan Hajek won singles matches over Germany's top two on Friday to knock the holders out of the World Team Cup and take the Czech Republic through to the final.
Berdych warmed up for the French Open, where he will be the 10th seed, by comfortably beating Philipp Kohlschreiber 6-3, 6-2.
Hajek then made certain of extending his side's unbeaten run in the Blue Group this week by seeing off Florian Mayer in a tougher 7-6, 6-2 victory.
The result dashed Spanish hopes of sneaking through on the final day of group matches. Spain were leading Belgium 2-0 in their match on court number one.
The Czechs will go on to face last year's runners-up Argentina, who finished top of the Red Group, in Saturday's final.