The gritty and relentless game of Djokovic matches up superbly against Federer's serene all-court game. The Serb has ruffled the Swiss maestro's feathers on quite a few occasions, upending his title ambitions at the biggest of tournaments on the tour.
One of only 8 players to have met Federer at each of the Grand Slams (the others being Tomas Berdych, Stan Wawrinka, Juan Martin del Potro, Jo-Wilfried Tsonga, Tommy Robredo, Mikhail Youzhny, and Nicolas Keifer), Djokovic is the only player to defeat Federer at all the four Grand Slam tournaments.
Of the above octet, only Djokovic, Berdych, Wawrinka, Del Potro and Tsonga have also met Federer at the season-ending ATP Finals, with only Djokovic and Del Potro managing multiple wins over the 20-time Grand Slam champion.
Djokovic, whose 26 career wins over Federer is the highest by any player to have beaten the 20-time Grand Slam champion, enjoyed a five-match win streak against Federer going into their clash at the 2019 ATP Finals. Only Rafael Nadal has enjoyed a similar win-streak (twice) against the Swiss maestro.
In a 'winner-takes-all loser-goes-home' virtual quarterfinal at the 50th ATP Finals, Federer and Djokovic faced each other for the 6th time at the season-ending tournament, with a place in the semifinals on the line. Federer, still smarting from two missed championship points on serve in the 2019 Wimbledon final against Djokovic, was in no mood for charity as he turned in a near flawless performance to beat the recently deposed World No. 1 6-4, 6-3 to romp into a record-extending 16th semifinal at the season-ending tournament.
The emotions knew no bounds as Federer leaped into the air in delight, akin to winning a tournament. This was his first win over Djokovic in 4 years and 6 matches, since a round-robin victory at the 2015 ATP Finals.
In the process, Federer registered his 23rd win over Djokovic, which is the joint-most he has beaten any player (also Stan Wawrinka), to improve to 23-26 in their riveting head-to-head rivalry.
On that note, let us re-live Federer's top five wins over Djokovic:
#5 2010 ATP Finals semis: Federer beat Djokovic 6-1 6-4
Going into their 2010 ATP Finals semifinal clash, Federer had enjoyed three wins in four meetings against Djokovic during the season. His only defeat against the young Serb had come in the US Open semis, where Federer failed to convert two match points.
In his 9th consecutive appearance at the ATP Finals, Federer breezed through the group stage without dropping a match, to book a semifinal meeting with Djokovic.
For the umpteenth time in his illustrious career, Federer made a brisk start, taking the opening set with two breaks of the Djokovic serve. After recovering from an early break in the second, Federer re-asserted his supremacy by breaking the Serb two more times to complete a 6-1 6-4 win and romp into his 5th final at the ATP Finals.
#4 2009 US Open Semifinal: Federer beat Djokovic 7-6(3) 7-5 7-5
In a dominant season, Federer beat Djokovic in straight sets in the US Open semis to reach his 4th Grand Slam final of the year.
The first set featured no breaks of serve and it went to a tiebreak, where Federer took charge by opening up a 5-2 lead en route to taking a one-set advantage.
In a competitive second set, Djokovic looked set to force another tiebreak, serving at 5-6 down, only for Federer to produce some dazzling play at the net to take a commanding two-set advantage.
It was now uncharted territory for Djokovic as no player had beaten Federer in 147 previous attempts in a Grand Slam after falling behind two sets. Djokovic survived break points at 3-4 in the third set but wouldn't recover from 0-30 down at 5-6, as Federer produced a stunning 'tweener' - much to the applause of Djokovic as well as the New York crowd.
Moments later, Federer sealed his passage to a sixth consecutive title match at the US Open.
#3 2011 French Open semifinals: Federer beat Djokovic 7-6(5) 6-3 3-6 7-6(5)
Following a stunning 41-0 start to the year, Djokovic faced Federer in the semifinals of the 2011 French Open.
Having beaten the Swiss maestro in their previous three meetings, Djokovic saw two set points at 4-5 come and go as Federer upped his game to take the first set on a tiebreak. Riding on his momentum, Federer took a commanding 4-1 lead in the second to gain a commanding two-set lead.
But Djokovic was not willing to give up just yet. Capitalizing on a slight dip in form from Federer, the Serb reduced the arrears and surged into a 3-0 lead in the fourth. He looked determined to become the first player in 175 attempts to beat Federer at a Grand Slam from two sets down.
Djokovic served for the fourth set at 5-4, but Federer clawed his way back into the match to force a tie-break. In a thrilling breaker, Djokovic cancelled out Federer's early mini-break advantage, but at 3-3 Federer won three consecutive points to arrive at three match points.
Although Djokovic saved the first two, he was powerless to save a third as Federer sent down his 18th ace of the match to complete a hard-fought win. That ensured he would return to the French Open final for the first time since his title triumph in 2009.
#2 2015 ATP Finals Round Robin: Federer beat Djokovic 7-5 6-2
Following defeats to Djokovic in the finals of Indian Wells, Rome, Wimbledon and the US Open earlier in the season, Federer faced Djokovic for the seventh time in the year, in the round-robin stage of the 2015 ATP Finals.
In one of the most dominating seasons on tour, Djokovic had reached all four Grand Slam finals (winning three) and reached a record eight Masters 1000 finals (winning six of them) as he arrived at the ATP Finals to complete the first 'four-peat' in tournament history.
Following an exchange of breaks, both players were solid on serve for large swathes in the set before Federer surged to a one-set lead by breaking at 5-5. Continuing his aggressive play, Federer rolled through the second set, caressing 19 winners en route to a 7-5 6-2 win and ending Djokovic's record 15-match winning streak at the tournament.
In converting four of his eight break points in the match, Federer also brought Djokovic's 23-match win streak in all competitions to an end.
#1 2019 ATP Finals Round Robin: Federer beat Djokovic 6-4 6-3
Facing his nemesis for the first time after a heartbreaking Wimbledon final loss where he failed to convert two championship points on serve in the fifth set, Federer turned in a lights-out performance under the lights at the O2 to register a dominating 6-4 6-3 win.
Following losses to Dominic Thiem in their previous two group games, both men faced off in a virtual quarterfinal. Djokovic had an early taste of what was on offer as he relinquished a 40-15 advantage on serve in the first game of the set.
Although Djokovic survived to hold, he fell to 0-40 in his next service game and never recovered. Federer rode on the lone break of serve to take the first set 6-4.
Djokovic looked to have stalled Federer's momentum when he survived two break points at 15-40 in the first game of the second to hold serve. But there would be no letting up from Federer.
Having failed to convert his lone break point of the match at 2-1, Djokovic ran into trouble on serve at 2-2 as Federer ripped blistering groundstrokes to puncture Djokovic's defence and grab the first break in the set.
With a vocal partisan crowd cheering for Federer, the Swiss maestro broke Djokovic again in the ninth game of the set and leaped in the air in delight - celebrating his first win in four years over the 32-year-old Serb.
Djokovic's loss ended his slim hopes of a record-tying 6th year-end World No. 1 ranking, and Federer moves to within two wins of becoming the oldest player to triumph at the ATP Finals.