Nadal sees off Wawrinka to retain number-one spot until 2014

Rafael Nadal will end the year as world number one after he overcame a strong challenge from world number eight Stan Wawrinka to record a 7-6, 7-6 victory at the World Tour Finals on Wednesday. The Spaniard's second win at the London event means he cannot now be caught by rival Novak Djokovic.

Far from having it all his own way as he had a day earlier against compatriot David Ferrer, Nadal was pushed on to the back foot by the Swiss’ accurate serve and flowing ground strokes. Both players carved out several break-point opportunities but only converted two apiece, Nadal digging deep in the ensuing tiebreaks to eke out a victory that rendered Djokovic’s win over Roger Federer on Tuesday night futile in terms of the world rankings. The Serb needed to win the tournament without losing a match to have a chance of knocking Nadal from the top of the rankings before 2014.

The world number one will next play Tomas Berdych as he seeks to secure a semifinal place at the Tour Finals, one of very few major tournaments in which victory still eludes him.