Updated

Andy Murray's 2013 season is off to a shaky start — a 6-3, 6-4 loss to Janko Tipsarevic on Thursday in the World Tennis Championship exhibition tournament.

Two early breaks in each set helped Tipsarevic dispatch the third-ranked Murray 6-3 in the opening match. The ninth-ranked Serb next faces Nicolas Almagro, a late replacement for Rafael Nadal who pulled out with a stomach bug.

Fifth-ranked David Ferrer defeated sixth-ranked Tomas Berdych 6-2, 6-4 to set up a semifinal against top-ranked Novak Djokovic, who won the tournament last year.