Del Potro off the mark in Tour Finals

Argentina's Juan Martin del Potro put himself back in contention at the ATP World Tour Finals today, beating Spain's Fernando Verdasco 6-4 3-6 7-6 in front of another near sell-out crowd at London's O2 Arena.

The U.S. Open champion, needing a win after losing to Britain's Andy Murray when round-robin action got under way on Sunday, failed to take a match point at 5-3 in the decider and saw another slip away in the following game as Verdasco hung on.

He forged 6-1 ahead in the tiebreak, however, and this time made no mistake, securing victory when Verdasco hit a forehand into the tramlines.

Tournament debutant Verdasco is now relying on Roger Federer beating Murray in the evening match in Group A to keep alive his slim hopes of reaching the semi-final.