Serbia shrug off Djokovic Davis Cup blow

Davis Cup champions Serbia shrugged off the injury-enforced absence of Wimbledon champion Novak Djokovic to take a 2-0 lead over Sweden in their quarter-final Friday and edge closer to a semi-final against Argentina. World number one Djokovic pulled out of his scheduled clash against world number 355 Ervin Eleskovic citing a knee injury. Despite the setback, Serbia were in control at the end of the first day in Halmstad against the seven-time champions with world number 16 Viktor Troicki beating Michael Ryderstedt 6-3, 6-1, 6-7 (6/8), 7-5 in the first singles rubber. World number 29 Janko Tipsarevic then stepped in for Djokovic and enjoyed a comfortable afternoon when debutant Eleskovic retired with a knee injury after the Serb had established a 6-2, 1-0 lead. \"I want to say at the start that it\'s a terrible way to win. I am really sorry for Ervin,\" said Tipsarevic. \"I am happy to give my country a point but I didn\'t want to win like this.\" The Serbia team have yet to decide whether Djokovic will play in the Sunday\'s reverse singles. In Buenos Aires, Argentina reached the semi-finals after Juan Ignacio Chela and Eduardo Schwank won their doubles rubber to establish a winning 3-0 lead over Kazakhstan. Chela and Schwank raced past Yuriy Schukin and Evgeny Korolev 6-3, 6-2, 7-5 to put the encounter to bed and set up a September meeting with either holders Serbia or Sweden. Former US Open champion Juan Martin Del Potro and Juan Monaco had set up the win on Thursday in easily winning their opening singles against Mikhail Kukushkin and Andrey Golubev. The tie was brought forward a day to end Saturday and avoid a clash with Sunday\'s elections in Buenos Aires. The Spaniards, seeking their third trophy in four years, are playing without World No. 2 Rafael Nadal, who pulled out of the tie to rest after reaching the Wimbledon final. The Americans need a victory from the world\'s top-ranked doubles squad, brothers Mike and Bob Bryan, over Lopez and Fernando Verdasco on Saturday to keep their hopes of advancement alive. In group play, Roger Federer came from a set behind to beat Rui Machado 5-7, 6-3, 6-4, 6-2 as Switzerland took a 2-0 lead over Portugal in Berne in their Europe/Africa second round tie. Federer last played Davis Cup for Switzerland in a play-off against Italy in 2009. Stanilas Wawrinka had given the Swiss the early lead in Friday\'s tie with a 7-5, 6-3, 6-4 win over Frederico Gil.