As expected, Davis Cup holders Serbia eased into this year\'s semi-finals after Janko Tipsarevic crushed Sweden\'s Michael Ryderstedt in their last-eight singles rubber here on Sunday Tipsarevic -- standing in for Novak Djokovic -- won the fourth rubber of the weekend in three straight sets (6-2, 7-5, 6-3) to secure Serbia a semi-final meeting with Argentina, themselves easy 5-0 winners against Kazakhstan. Ryderstedt, who was playing his first ever Davis Cup with a world ranking of 297, had put up a good fight but lost to Viktor Troicki in the first rubber on Friday. Tipsarevic then gave Serbia a 2-0 lead, getting past Ervin Eleskovic when he retired injured. The hosts did see their hopes rekindled on Saturday when Simon Aspelin and Robert Lindstedt won the doubles rubber in straight sets, defeating Wimbledon champion and world number one Djokovic and Nenad Zimonjic, who ranks sixth in the world for doubles. But on Sunday, Tipsarevic clearly had the upper hand, breaking Ryderstedt no fewer than six times en route to victory. Troicki and Lindstedt are playing in the final rubber of the weekend.