Isner, Querrey win for United States
Need the scores from any match played in today's tournaments? Results
The match was played in a largely empty stadium after several rain delays disrupted the schedule.
Each series in the round-robin format consists of two singles and a doubles match, played over two days. The winner of each group will meet in Saturday's final.
Argentina beat Serbia after Juan Monaco rallied for a 1-6, 6-3, 7-6 (3) win over Viktor Troicki for a 2-0 lead after the singles. Troicki then teamed with Nenad Zimonjic to beat Eduardo Schwank and Horacio Zeballos 6-1, 3-6, 10-8 in a meaningless doubles match.
Copyright 2010 by The Associated Press