Looking back at Roger Federer's last 5 semifinals at the ATP Finals

Roger Federer proved for the umpteenth time that age is just a number when he turned in a virtuoso, near-flawless performance to beat Novak Djokovic for the first time in 4 years and 6 matches. In the process, the Swiss maestro reached a record-extending 16th semifinal at the ATP Finals, in his record-extending 17th appearance at the season-ending tournament.

Federer has a rich resume at the ATP Finals. He is the tournament's all-time title leader with most titles (6) and most finals (10), has played the most matches (75), has had the most wins (59) and has won at least a match in each of his 17 appearances, failing to negotiate the group stage only in 2008.

The Swiss maestro is now just two wins away from extending his record of being the oldest player to triumph at the ATP Finals. The then 30-year-old had picked up his sixth and latest trophy at the ATP Finals in 2011.

On the eve of Federer's 16th semifinal at the ATP Finals, where he'll take on young Greek Stefanos Tsitsipas, let us have a flashback of how the Swiss maestro has fared in his last 5 semifinals at the season-ending tournament.

#1 2018 Semifinal: Lost to Alexander Zverev 5-7 6-7 (5)

Roger Federer

Federer started his 16th appearance at the ATP Finals on the wrong note, when he went down to Kei Nishikori in straight sets for his first loss in his first round-robin match in 5 years. The Swiss maestro recovered by beating Dominic Thiem and Kevin Anderson in straight sets in his next two matches to advance to a record-extending 15th semifinal at the season-ending tournament.

In an evenly contested first set, Zverev made his move in the 12th game to take the opener. The second set was another tight affair as Federer forced a tiebreak.

Despite the distraction of a ball boy in Zverev's eyeline dropping the ball during the 3-4 point in the tiebreak, which led to a section of the pro-Federer crowd unjustifiably booing the young German, Zverev served an ace on the point replay and went on to close out a 7-5 7-6(5) victory.

Zverev went on beat Novak Djokovic in the final to lift the biggest title of his career and become the first player to beat Federer and Djokovic in back-to-back matches at the ATP Finals.

#2 2017 Semifinals: Lost to David Goffin 6-2 3-6 4-6

Federer greets Goffin at the net after his semifinal loss to the Belgian

Enjoying a remarkable season after the first significant injury layoff of his career, Federer won two Grand Slam titles (Australian Open and Wimbledon) for the first time in 10 years and three Masters 1000 titles (Indian Wells, Miami, Shanghai), for a total of seven titles from eight finals as he arrived at the 2017 ATP Finals.

Federer beat tournament debutant Jack Sock, Alexander Zverev and Marin Cilic to go unbeaten at the ATP Finals group stage for a record-10th time in his career. In the semifinals, Federer was a runaway favourite against David Goffin, whom he had not lost to in six career meetings, and against whom he had dropped only three games in their last meeting in the Basel semifinals.

The Swiss maestro looked set to improve his dominance over Goffin to 7/7 when he breezed through the first set 6-2. But the script turned as Goffin broke early in the second and held on to restore parity at one set apiece.

Riding on his momentum, Goffin broke in the third game of the third and never looked back. He completed his first victory over Federer in seven attempts, and in the process reached his first big final (Grand Slam, ATP Finals, Masters 1000) - where he went on to lose to Grigor Dimitrov.

#3 2015 Semifinals: Beat Stan Wawrinka 7-5 6-3

Roger Federer and Stanislas Wawrinka meet at the net

In his 14th appearance at the ATP Finals, Federer beat Tomas Berdych in his first round-robin match before ending three-time defending champion Novak Djokovic's 15-match win streak at the tournament in his next match. The Swiss maestro saw off Kei Nishikori in three sets to book a semifinal with his compatriot Stan Wawrinka, in a repeat of the pair's epic last-four clash from a year ago.

Federer recovered from an early break down to take the opener 7-5. He rode his momentum to an early break in the second which he never relinquished, as he went on to beat his good friend at the last-four stage of the ATP Finals for the second time in as many years.

In the process, Federer reached a record-extending 10th final at the ATP Finals, where he lost to Djokovic.

#4 2014 Semifinals: Beat Stan Wawrinka 4-6 7-5 7-6(6)

Federer beat Wawrinka in the 2014 ATP Finals semifinals

Federer breezed through the group stage without dropping a set, beating Milos Raonic, Kei Nishikori and Andy Murray to reach a 12th semifinal at the ATP Finals. There, he met the reigning Australian Open champion and good friend Stan Wawrinka.

Federer dropped his first set of the tournament as Wawrinka took a one-set lead. The 17-time Grand Slam champion then fought back to take the second set 7-5 to force a decider.

In a highly competitive third set the momentum shifted back and forth as Federer, irked by an over-rule by the chair umpire, dropped serve in the opening game.

Wawrinka squandered three match points when serving for the match at 5-4 as the match went to a tiebreak. The 'other Swiss' saw another match point come and go before Federer made good on his first opportunity to reach his ninth final at the ATP Finals.

#5 2013 Semifinals: Lost to Rafael Nadal 5-7 3-6

Nadal beat Federer in the 2013 semifinals

Having lost to Novak Djokovic in his opening round-robin match, Federer beat Richard Gasquet in straight sets before recovering from 0-3 down to beat Juan Martin del Potro 7-5 in the third and reach his 11th semifinal at the ATP Finals.

Facing Rafael Nadal for the fifth time in the tournament, Federer looked to seize the early initiative but lost serve at 4-4 as Nadal rained down some ferocious forehands. Federer fought back in the next game to get back on serve, only for Nadal to ride on another errant service game from Federer to take the opening set 7-5.

Federer continued to struggle on serve in the second set, dropping serve at 2-2. He got broken again in the ninth game of the set as Nadal registered his first victory at the ATP Finals in five attempts over the six-time champion.

Nadal went on to lose to Djokovic in the final.