Prague: Tomas Berdych and Radek Stepanek used a roaring home crowd to come back from a set down on Saturday, putting the Czech Republic 2-1 up over holders Spain and a win away from the Davis Cup title.
The Czech pair looked tired from the opening singles matches that went late on Friday but triumphed 3-6 7-5 7-5 6-3.
Spain's top duo of Marcel Granollers and Marc Lopez silenced the 14,000-strong crowd early on, cutting short a Czech rally in a crucial seventh game that helped them cruise in the first set.
But the Czechs shook off the slow start by racing ahead in the second set to get the crown going again.
A couple of unstoppable overhead smashes gave the Czechs the second set and they took control of the match by winning the third with a Berdych backhand volley and then easing through the fourth set.
"They started really on a high... and hit incredible shots," Stepanek said.
"We knew what we are capable of doing in Davis Cup. We have played together so many times. Plus with Tomas coming off a four-hour match (on Friday) and coming so strong here today, it just shows the desire and hunger we have for the trophy."
The Czech pair improved their doubles record to 12-1, with their only loss together in 2009 when Spain trounced the team 5-0 in the final that year.
World number six Berdych will hope to take that momentum into the first singles match on Sunday against fifth-ranked David Ferrer.
A win would give the Czech Republic its first Davis Cup crown in 32 years and end Spain's bid for a fourth title in five years.