Tramlines takes a look back at the incredible rivalry between Roger Federer and Novak Djokovic: one of the best ongoing duels ever.

Truly great rivalries are hard to come by, but between Roger Federer, Rafael Nadal and Novak Djokovic, tennis fans have been richly treated in recent years.

The trio are all recognised as legends of the game, but Tramlines has noticed that, when great tennis rivalries are cited, Federer and Djokovic's duels are rarely mentioned.

It's time to put that right, with the pair set to tussle it out again at the US Open at Flushing Meadows.

World number one Federer secured his sixth ATP title of the year with an impressive 6-0 7-6 win over Novak Djokovic in the Cincinnati Open final, and he has now equalled the 21 Masters 1000 titles won by Nadal in the elite series.

The 31-year-old took the first set 6-0 in just 20 minutes, but he has not consistently dominated the Serb over the years, leading the pair's head-to-head record 16-12.

Federer also boasts a 4-3 lead over Djokovic in Championship matches, after the pair faced off for the seventh time in a tour-level final - from the 28 times they have locked horns, there have been some truly classic encounters.

2007 - US Open final - Federer won 7-6(4) 7-6(2) 6-4

Federer, who came into the match as the world number one of a staggering 188 weeks in succession, overcame the major final debutant Djokovic, who was just 20-years-old at the time. "My next book is going to be called, 'Seven Set Points'," Djokovic said after squandering five set points in the first set, and two in the second to falter under immense pressure from his more experienced opponent. Federer lauded the young Serb after revealing how challenging it would be to fend off the 'new challengers'.

2008 - Australian Open semi-final - Djokovic won 7-5 6-3 7-6(5)

What does it take to beat Federer? Well, after beating the Swiss in this pulsating three-setter, Djokovic would have told you 'just 13 aces and 50 winners!'. This time it was Federer who squandered set points as Djokovic compiled an 11-game winning streak which changed the match. Federer, who had been bidding to reach his 11th straight Major final, said afterwards, "I've created a monster". It would prove to be a defining moment in the Serb's career.

2008 - US Open semi-final - Federer won 6-3 5-7 7-5 6-2

In a rematch from the previous year, Federer had the better of an incredible flurry of breaks as he destroyed the Djokovic serve. The Serb saved countless break points, but Federer would not be denied as he hit 20 aces and lost his serve just twice in the match, producing a staggering 51 winners. It was a majestic performance from the Swiss.

2009 - US Open semi-final - Federer won 7-6(3) 7-5 7-5

The scoreline may make this match appear to be a relatively comfortable victory for the Swiss, but it will always be remembered for a shot which he still calls "the greatest of my career". Djokovic was already celebrating a stunning lob as Federer somehow managed to retrieve the ball, before unleashing an incredible through-the-legs trick shot which prompted a wild standing ovation. "It's the greatest shot I will ever hit in my life," he said. It was worthy of a magnificent victory.

2009 - ATP Basel final - Djokovic won 6-4 4-6 6-2

It may have been an ATP World Tour 500 event final, but it was undoubtedly significant. Federer has always proudly marked the Swiss Indoors Basel tournament in his diary, and the three-time defending champion was usurped at his hometown event. A 22-minute 10th game left both players on their haunches, with both players having to dig deep in a series of epic rallies. Federer's 19-match unbeaten run in Basel was ended abruptly, and it was a crushing disappointment for him.

2010 - US Open semi-final - Djokovic won 5-7 6-1 5-7 6-2 7-5

Djokovic's victory was undoubtedly a significant mental hurdle to overcome after having lost to his great rival for three consecutive years at Flushing Meadows. The Serb saved two match points with sensational winners and, fittingly, he closed it an enthralling match by winning a 22-shot rally with a ferocious forehand. The victory over the five-time US Open champion left Djokovic very emotional, and he reflected, "that's why (Federer) is the best player that has ever played the game".

2011 - Australian Open semi-final - Djokovic won 7-6(3) 7-5 6-4

Having been comprehensively defeated by Federer in their previous meeting at the World Tour Finals in London, Djokovic sought revenge in the first major of the year. A tense opening set was eventually decided on a tie-break with Federer blown off the court by his ultra aggressive opponent. The Serb reeled off five successive games to win the second set with some breathtaking shots, and a break from 4-4 in the third game him a memorable victory.

2011 - French Open semi-final - Federer won 7-6(5) 6-3 3-6 7-6(5)

Federer came into the match having lost three big matches to the Serb, but he avenged those defeats, ending his opponent's remarkable winning streak of 41. The first set took fully 70 minutes with the standard exceptionally high, and it did not relent thereafter. Federer eventually closed out a superb win with his 18th ace of the match in very poor light late in the evening in Paris. He was magnanimous in defeat: "I thought it was a great match from both sides".

2011 - US Open semi-final - Djokovic won 6-7(7) 4-6 6-3 6-2 7-5

Many believed that the thrilling semi-final between the pair the previous year could not have been bettered, but this was even more dramatic. In their 24th contest, both players traded breathtaking winners from the back of the court with Djokovic outplayed in the opening two sets. What ensued was one of the most memorable comebacks in tennis history as Djokovic roared back to beat the sport's greatest ever player in five sets. Federer led 5-3 in an enthralling final set, and squandered two match points as Djokovic defied the odds to come through and claim an unbelievable win.

2012 - French Open semi-final - Djokovic won 6-4 7-5 6-3

Federer surprised everyone by approaching the match with an ultra-aggressive gameplan, and it produced a typically entertaining contest as the Swiss went for his shots to mixed results. Djokovic was faultless on serve as he took the opening set in 34 minutes, before Federer squandered three break points for a 4-2 lead in the second and went on to lose it 7-5. The Swiss's serve crumbled in the third set, and Djokovic was given the opportunity of becoming the first player since Rod Laver in 1969 to hold all four Grand Slam titles as a result of his victory.

2012 - Wimbledon semi-final - Federer won 6-3 3-6 6-4 6-3

Federer was at his imperious best under a closed roof on Centre Court, and he broke serve in the sixth game en route to taking the opening set in just 24 minutes, having committed just two unforced errors. Djokovic produced a quite brilliant performance to take the second set in equally resounding fashion, before a dramatic eight-minute game left the third set set intriguingly poised with the Serb winning 23 and 25 stroke rallies to hold at 3-2. Federer still managed to come through and win the set, before storming through the fourth to seal a place in his 24th Grand Slam final. He went on to win his eighth Wimbledon title and reclaim the world number one ranking.

Dan Quarrell / Eurosport