Sweden's Ervin Eleskovic retired with a knee injury in the second set against Serbia's Janko Tipsarevic to hand the defending champion a 2-0 lead in their Davis Cup quarterfinal Friday. In the first match, Serbia's Viktor Troicki overcame a late challenge by Michael Ryderstedt to win 6-3, 6-1, 6-7 (6), 7-5. More...