Novak Djokovic beats Rafael Nadal to win World Tour Finals
Novak Djokovic retained his ATP World Tour Finals title with a convincing win over world number one Rafael Nadal.
The Serb, who lost the top ranking to Nadal last month, won 6-3 6-4 at the O2 Arena in London.
Djokovic, 26, extended his unbeaten run to 22 matches as he claimed the season-ending title for the third time.
He will now head to Belgrade, where Serbia take on the Czech Republic in the Davis Cup final from Friday.