With Serbia leading the best-of-five series 2-1, the top-ranked Djokovic gave Serbia an insurmountable lead when he put away Querrey 7-5, 6-7 (4-7), 6-1, 6-0 in a 2-hour, 35-minute match.
Serbia had grabbed the lead Saturday when the doubles tandem of Nenad Zimonjic and Ilija Bozoljac staged a marathon upset of the world No. 1 team of Bob and Mike Bryan, 7-6 (7-5), 7-6 (7-1), 5-7, 4-6, 15-13.
Serbia goes on to face Canada, which prevailed against Italy Sunday.
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