The world tennis number one Novak Djokovic had to save a match point in the third set to defeat Tomas Berdych 3-6 6-3 7-6 in his opening match at the ATP Tour Finals in London.
Berdych held match point when he was up 6-5 in the deciding set only to put a forehand into the net.
Djokovic, who's nursing a shoulder injury, has won three grand slam titles this season but has been struggling with back and shoulder problems since winning the US Open.
He joins Spain's David Ferrer at the top of Group A in the round robin competiion.
Ferrer had a straight sets win over Scotland's Andy Murray.
