Rafael Nadal was forced to withdraw from the Paris Masters with an abdominal injury, sending Novak Djokovic to the top of the ATP rankings.

World number one Nadal had been set to face compatriot Fernando Verdasco on Wednesday, but he announced shortly before the scheduled start time that he would not be fit to play.

With Djokovic only needing to better Nadal's performance in Paris to take top spot, the Wimbledon and US Open champion will become world number one for the first time in almost two years next week.