(CNN) -- Novak Djokovic confirmed his status as World No.1 and denied Roger Federer a seventh title at the ATP World Tour Finals with a straight sets victory over his Swiss opponent at the O2 Arena Monday.
The Serbian closed out victory after two hours 14 minutes of enthralling tennis, thumping his chest in trademark style to celebrate a 7-6 7-5 victory.
He had trailed in each set to a break of service before hitting back in tenacious style to ultimately frustrate 17-time grand slam champion Federer.
Both men came into the end of season showpiece in possession of a single grand slam title in 2012 and having held the coveted No.1 spot, Djokovic taking it back when Federer skipped the preceding Paris Masters.
But it was Djokovic who put the seal on another triumphant season with his second victory in the Tour Finals after 2008, picking up the check for $1.7 million.
"Congratulations to Novak on an amazing tournament and an amazing year, You are the best. It has been an amazing year for me too," Federer said.
Federer would have been energized by the raucous reception he received at the start of the match from an expectant capacity crowd and he did not disappoint in the opening exchanges.
He won the first nine points to break service and hold for 3-0 in a purple patch to match the color of his tennis shirt.
But all season Djokovic has shown an incredible tenacity and here it was no exception.
Federer's 3-0 lead was erased as he broke back and then broke again to lead 5-4 and serve for the set.
But Federer saved one set point before taking his first opportunity to break back to level at 5-5.
The quality of the tennis was undeniable and it continued into the tiebreaker where Djokovic twice edged ahead with mini breaks only for Federer to retrieve the situation.
He saved one set point with an incredible lunge at 5-6 but lost the next two points as Djokovic closed out the opener.
Federer might have been expected to be deflated but he gained an early break in the second set and held the advantage until serving to level at 5-4 where he frittered away a 40-15 lead.
Djokovic was not going to be denied and swept through the next two games, breaking Federer for the fourth time in a pulsating match to take the title.
It was only the fourth time in the 43-year history of the Tour Finals that the top two in the world rankings had met in the final and it had fully lived up to expectations.
Federer, who had beaten home hope Andy Murray in the semifinals, was losing for only the second time in eight final appearances as he chased a hat-trick of titles.