The greatest rivalry in men's tennis takes center stage again at the US Open on Sunday when world No. 1 Novak Djokovic and 17-time Grand Slam men's singles champion Roger Federer do battle inside Arthur Ashe Stadium to decide the final major of the year.

Djokovic and Federer have met 41 times in their careers, starting in 2006 when the pair first squared off on the clay of Monte Carlo, with Federer holding the narrowest of edges, up 21-20. He also leads, 16-14, on hard courts.

Their six most recent contests, and eight of their past 10, have been in finals. In total, the pair has played 16 finals and another 21 semifinals against one another. 

They have also met 13 times in Grand Slams, with Djokovic leading that particular head-to-head, 7-6. They have split their eight hard-court matches at Slams at four apiece, with Djokovic holding a 2-1 advantage in Australia and Federer leading their US Open matchups, 3-2. They have shared their two matches at Roland Garros and Djokovic leads, 2-1, on the grass of Wimbledon.

Of those matches at Slams, three have been in finals: Federer triumphed at the 2007 US Open and Djokovic beat the Swiss for the trophy in each of the past two years at Wimbledon.

What makes their rivalry even more exciting is that there's rarely been a blowout and neither player has ever won more than three consecutive matches against the other since Federer won their first four career meetings, which began when Djokovic was still a teenager.

The pair has contested 120 sets, exactly half of which have been decided by a score of 6-4, 7-5 or 7-6. Just five have been 6-1 sets and only once, in Cincinnati three years ago when Federer won the title, has a bagel been thrown up on the scoreboard. Eight matches have seen a player rally from at least a one-set deficit, including two of the most memorable matches ever played in Arthur Ashe Stadium.

Here's a look at Djokovic and Federer's history in New York City.

2007 Final: Federer def. Djokovic, 7-6, 7-6, 6-4

Federer won the fourth of five consecutive US Open championships in the second-longest straight-sets men’s final in recorded US Open history.

Federer was not at his best, but he took advantage of a nervous 20-year-old opponent competing in his first major final. Djokovic led 6-5 in each of the first two sets, squandering five set points in the opening set and two in the second. Federer erased those and dropped just six points combined in the two tiebreaks that ensued.
Chances became few and far between in the third set. Djokovic had three break points at 0-40 on the Federer serve at 2-2, but Federer won the next five points and never looked back en route to a 6-4 victory.

Between 1970 and 2005, no man had reached all four Slam finals in the same calendar year. But with Federer’s trip back to the final in Flushing, he had achieved the feat twice in a row. With his win, and victory in the overall Emirates Airline US Open Series title, Federer earned the largest payout in tennis history, $2.4 million.

2008 Semifinal: Federer def. Djokovic, 6-3, 5-7, 7-5, 6-2

In the first of the two semifinals, No. 2 seed Federer won a four-set battle with third-ranked Djokovic to keep his bid for a fifth consecutive crown in the Big Apple alive.
After winning three Slams in each of the previous two years, Federer entered the 2008 US Open with none of the first three majors of the season.

Federer broke for a 3-1 lead in the first set and committed just three unforced errors in racing out to a 6-3 advantage. Djokovic earned his first break at 1-2 in the second set and jumped out to a 4-1 lead. Federer saved two set points at 5-6, but sprayed a backhand wide to help the Serb pull level.

The first 10 games of the third set went with serve until Federer secured a decisive break in going 7-5 ahead, and Federer then won the final four games of the match to book his place in his fifth US Open final.

2009 Semifinal: Federer def. Djokovic, 7-6, 7-5, 7-5

At the time, the ’09 semifinal went down in history as the match in which Federer played his greatest ever shot.

With Djokovic serving at 5-6, 0-30 in the third set, the five-time defending champion ripped a tweener down Djokovic’s forehand wing for a clean winner. The shot literally brought the crowd to its collective feet and figuratively sent Djokovic to his knees.

The match was more even than the straight-sets scoreline suggests, with Djokovic going up an early break in the first set, only to see Federer storm back and take the tiebreak with a forehand winner at 5-2 and a drop shot volley the following point.

Djokovic almost sent the second set to another ‘breaker, but Federer played the key points better and broke with the 22-year-old serving to stay in the set at 5-6. In the third set, Djokovic saved break points at 3-4 and Federer did the same at 4-4, but it was the champion who emerged the victor with a forehand return winner to return to the final.

2010 Semifinal: Djokovic def. Federer, 5-7, 6-1, 5-7, 6-3, 7-5

In one of the all-time classic semifinals, Djokovic avenged his US Open defeats to Federer over the past three years in a five-set thriller, the first men’s semifinal to go the distance since Andre Agassi defeated Robby Ginepri in 2005.

Djokovic trailed by a set to love and later by two sets to one, but he dug deep and found a way to unseat the man who had been in the past six finals in the Big Apple.
In a match that finished just shy of the four-hour mark, Djokovic erased a tough first-set loss by racing through the second in just 29 minutes, the first 6-1 set Federer had lost in New York since 2008. Federer was uncharacteristically sloppy – he made 65 unforced errors – but that took nothing away from one of the all-time fighting performances to topple the man who had dominated here for half a decade.

Federer grinded out the third set to move one win away from another Federer-Nadal finale, but Djokovic raced out to a 4-1 lead in the fourth set behind consecutive breaks of the normally impenetrable Federer serve.

Djokovic saved two match points in the fifth set and then broke Federer at 5-5 to put him on the cusp of his first US Open final. Federer had one last chance to break back, but his forehand flew long and Djokovic wrapped up the three-hour, 54-minute semifinal three points later when another Federer forehand sailed wide.

2011 Semifinal: Djokovic def. Federer, 6-7, 4-6, 6-3, 6-2, 7-5

A year after losing in his first US Open final to Nadal, Djokovic returned to the final with another memorable victory over his nemesis.

Djokovic became just the sixth player, and fifth man, to win the US Open after being match point down earlier in the tournament. Djokovic saved two match points of Federer’s serve in the fifth set of their semi to knock off the five-time champion. Trailing 5-3, 40-15, Djokovic saved the first match point with a blistering cross-court forehand return that landed squarely on the sideline. On the second, Federer made an unforced error on a forehand as Djokovic rallied to win the final four games.

After an hour-long rain delay delayed the start of the semifinal, both men came out playing their attacking brand of baseline tennis. Federer needed five sets to wrap up the first-set tiebreak and was forced to wait until the seventh game of the second set to earn his first break of the match.

Down two sets to none, Djokovic rekindled the form which had seen him go 62-2 on his way to the semis. He took the third set 6-3 and then dropped just three points on his serve in the fourth to push Federer to another deciding set. Federer failed to serve it out at 5-3 and Djokovic seized upon the new-found momentum to topple Federer for the second year in a row.