James Blake lost 5-7, 6-3, 6-0 to undefeated Robin Soderling and Thomas Johansson stopped Bobby Reynolds 6-3, 2-6, 6-3.
Also in the Red Group, Argentina and the Czech Republic are tied 1-1. In the Blue Group, Russia leads Germany 1-0 and Spain leads Italy 1-0.
The winner of the Blue Group will face Sweden in Saturday's final.
Blake, ranked No. 8, tried to remain upbeat heading into the French Open, which starts Sunday.
"Hopefully this match will not affect me,'' Blake said of his second loss in three matches. "I'll put these last couple of sets out of my mind and get ready for Paris. Maybe it's easier to go there that way, than going down with a real tight one and thinking I can't close out matches.''
Tomas Berdych defeated Guillermo Canas 6-2, 3-6, 6-3 to give the Czechs an early lead before Juan Ignacio Chela stopped Michal Tabara 6-0, 6-4.
Spain got its point from David Ferrer, who defeated Potito Starace of Italy 6-3, 3-6, 6-3. Igor Andreev put Russia ahead of Germany by defeating Philipp Kohlschreiber 6-4, 6-3.
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