Spain reached their sixth Davis Cup final in 10 years after David Ferrer gave them an unassailable 3-1 semi-final lead over the United States by beating John Isner 6-7 (3/7), 6-3, 6-4, 6-2 on Sunday.
Spain will travel to either Argentina or the Czech Republic for the final, depending on which of those countries prevails in the other semi-final due to be decided later on Sunday in Buenos Aires.
The United States had kept the tie alive with the five-times champions with a doubles victory by the twins Bob and Mike Bryan on Saturday, but US Open semi-finalist Ferrer on his favourite red clay prevailed over Isner, the world number 10.
The six-foot, nine-inch American beat Ferrer in a tie-break in the first set but the Spaniard dominated the following three.
Ferrer, currently number one in his country in the absence of injured Rafael Nadal, tamed Isner's formidable serve and aggressive style with precision returns and passing shots and capitalised on a series of unforced errors.
It was the 16th Davis Cup victory in a row for Ferrer on clay.