ATP Finals: Looking back at the 5 previous clashes between Djokovic and Federer at the season-ending tournament

#4 2015 RR: Federer beat Djokovic 7-5 6-2

Federer and Djokovic after their 2015 round-robin match

Djokovic and Federer were perched in the same group at the 2015 ATP Finals, for the second time in their career. Three-time defending champion Djokovic was coming off a record 15-match win streak at the tournament when he took on Federer in the second round-robin match.

In their seventh meeting of the season, Federer capitalized on a loose Djokovic service game late in the first set to take the opener 7-5. He subsequently rode his momentum to a 7-5 6-2 win, for his second win of the season over the World No. 1.

With the win, Federer avoided falling behind in their rivalry for the very first time, by taking a 22-21 lead in their head-to-head. The Swiss maestro would go on to reach another final at the ATP Finals, but he was made to wait for a record-extending 7th title at the tournament.

#5 2015 Final: Djokovic beat Federer 6-3 6-4

Djokovic capped off a dominant season with his 5th ATP Finals title

After squaring off in the group stage earlier in the tournament, Federer and Djokovic met in the title match of the 2015 ATP Finals. It was the pair's 7th final of the season, with Djokovic leading 4-2 following wins at Indian Wells, Rome, Wimbledon and the US Open.

An erratic Federer struggled with the consistency of Djokovic as the six-time champion dropped serve twice in the first set to concede the opener. Federer improved in the second set, but a relentless Djokovic remained unerring from the baseline to complete a 6-3 6-4 win.

With the victory, Djokovic became the first player to win four successive titles at the tournament, and drew level with Ivan Lendl and Pete Sampras as five-time winners at the ATP Finals. It was a career-best season which saw the Serb reach a record eight Masters 1000 finals, win a record six Masters 1000 titles, reach all four Grand Slam finals, and win 11 titles.

During the course of his win in the final, Djokovic won a staggering 84% of points behind his second serve (62% points won on first serve).