World No. 6 David Ferrer defeated 10th-ranked hometown hero Andy Roddick to give Spain a 2-0 lead on Friday after the opening day of their Davis Cup quarter-final tie.
The Spaniards, seeking their third trophy in four years, moved to the brink of victory in the best-of-five matchup when Ferrer downed Roddick 7-6 (11/9), 7-5, 6-3.
Spain had seized the lead in the opening singles match when Feliciano Lopez outlasted eighth-ranked Mardy Fish in a four-hour showdown 6-4, 3-6, 6-3, 6-7 (2/7), 8-6.
The Americans need a victory from the world's top-ranked doubles squad, brothers Mike and Bob Bryan, over Lopez and Fernando Verdasco on Saturday to keep their hopes of advancement alive.
Opponents will be reversed in Sunday's singles matches and the Americans would need to win both of those as well as the doubles to deny the Spaniards, who won titles in 2004, 2008 and 2009.
The Spanish are playing without World No. 2 Rafael Nadal, who pulled out of the tie in order to rest after reaching the Wimbledon final.