LONDON: Britain's Andy Murray laboured to a third set tie-break victory over Spain's Fernando Verdasco in their final Group A game at the World Tour Finals on Thursday.

Murray won 6-4, 6-7 (4/7), 7-6 (7/3) in three hours at London's O2 Arena, eliminating the Spaniard from the competition but leaving his own chances of reaching the semi-finals in the balance.

Murray must wait for the result of group leader Roger Federer's match against Argentina's Juan Martin del Potro later Thursday to see whether he has made the last four of the season-ending tournament of the world's top eight players.