Tennis: World Tour Finals - 2009 - Final: Nikolay Davydenko v Juan Martin Del Potro

Live coverage of the Barclays ATP Tour World final at London's O2 Arena, presented by Sue Barker. Today's match brings down the curtain on a gruelling season for the world's top players, but both finalists will be determined to end the year on a high by claiming the title. Russia's Nikolay Davydenko takes on Argentina's Juan Martin Del Potro.