Without Djokovic, Argentina leads Serbia 2-0
{{#rendered}} {{/rendered}}In the absence of Novak Djokovic, defending champion Serbia lost both its matches Friday to trail Argentina 2-0 in the Davis Cup semifinals.
Argentina's David Nalbandian beat Viktor Troicki 6-4, 4-6, 6-2, 6-3, and Juan Martin del Potro topped Janko Tipsarevic 7-5, 6-3, 6-4.
Djokovic pulled out of the opening singles because of back pain, four days after beating Rafael Nadal in the U.S Open final. He was replaced by Troicki.
{{#rendered}} {{/rendered}}Nalbandian had little trouble against his replacement, who had 58 unforced errors at an indoor hard court in Belgrade Arena.