Sam Querrey rallied for a five-set victory over Viktor Troicki that enabled the United States to even their Davis Cup quarterfinal showdown with Serbia at 1-1 after Friday's first day of singles play.
The Serbs had grabbed an early advantage after world No. 1 Novak Djokovic posted a 7-6 (7-5), 6-2, 7-5 triumph over John Isner in the tie's opening match from Taco Bell Arena.
Troicki, subbing for injured world No. 9 Janko Tipsarevic, appeared on the verge of putting Serbia up 2-0 in the best-of-five tie after taking two of the first three sets against Querrey. The 6-foot-6 American dominated the fourth, however, then fought back in the fifth to post a 7-6 (7-1), 3-6, 4-6, 6-1, 6-4 decision that took three hours and 20 minutes to complete.
Up 5-4 in the final set, Querrey scored a critical break of Triocki before serving out the match to improve to 3-0 in Davis Cup play this year.
Djokovic didn't have an easy time either against the towering Isner, who peeled off 17 aces in the match. The Serbian star was able to break Isner four times, however, and claim a hard-fought first-set tiebreaker to prevail in exactly two hours.
Play will resume Saturday with a doubles rubber between the outstanding American twin Bryan brothers, Bob and Mike, against a Serbian duo of Ilija Bozoljac and Nenad Zimonjic. Sunday's reverse singles call for the Australian Open champion Djokovic to battle the 20th-ranked Querrey and the world No. 23 Isner to take on the 44th-ranked Troicki.
Serbia topped the 32-time titlist U.S. 3-2 in Belgrade in an opening- round tie three years ago in their lone previous Davis Cup meeting.
Team USA is captained by Jim Courier, while Bogdan Obradovic is guiding the visiting Serbs.
The winner of this quarterfinal tie will meet the Canada-Italy victor in the semifinals in September.