Tennis: Djokovic books Nadal title showdown in Tour Finals

Novak Djokovic set up a final showdown with Rafael Nadal as the defending champion cruised to a 6-3, 6-3 victory over Stanislas Wawrinka in the semi-finals of the ATP World Tour Finals on Sunday.

Djokovic extended his winning streak since the US Open to 21 matches and will bid for his third Tour Finals crown when he faces world number one Nadal in Monday's final at London's O2 Arena.

"It was a very enjoyable match for me, it was my best performance at the tournament so far," said Djokovic.

Nadal, who put out Roger Federer in his semi-final, will take a 22-16 career lead over Djokovic into Monday's final.