It's one of the greatest rivalries in tennis, currently standing at 57 matches, encompassing Grand Slams, Masters, Olympics and Davis Cups.
Chances are that Rafael Nadal and Novak Djokovic will meet once again next month in the final at Roland Garros, the very place where they first clashed in 2006.
AFP Sport looks back on that day 15 years ago:
-- Second seed Nadal was the defending champion in Paris having won the first of his 13 Roland Garros titles, and 20 majors overall, 12 months earlier at the age of 19.
Djokovic, world number one now, was then a brash 19-year-old ranked at 63.
Against Nadal, he insisted he had nothing to lose.
"I'm going out there to win, not just play," said Djokovic who had defeated three top 30 players to reach the quarter-finals.
For Nadal, it hadn't all been plain sailing with the young Spaniard needing four sets to get past Paul-Henri Mathieu and Lleyton Hewitt in the previous two rounds.
-- Djokovic was hoping the French crowd would get behind him on Court Philippe Chatrier. He had even donned a France football team jersey in his pre-match media conference hoping to tap into the national feelgood mood which would see Les Bleus reach the final of the World Cup in Germany that summer.
Unfortunately, the early afternoon start meant that most of the courtside seats were empty. Not even Nadal and Djokovic could compete with the attractions of lunchtime schmoozing in the nearby VIP restaurants.
Dressed in his white pedal-pushers, Nadal broke first, but Djokovic hit back. Nadal carved out another break for 2-1 and that was enough for the first set 6-4.
Both players exhibited mannerisms and habits which would become common-place over the next 15 years.
Commentators were intrigued by the number of times Djokovic bounced the ball between serves -- "14, 15, 16".
At the other end, cameras picked out 'Vamos' scribbled in pen on the heel of Nadal's right shoe.
The champion, shoulder-length hair kept under control by a white bandana, was not wasting too much time, despite a fussy service action punctuated by a now familiar straightening of his shorts and mopping of his brow.
In no time at all, he was a double-break up for 3-0 before Djokovic retrieved one break to trail 2-4.
In between, Djokovic had taken a nasty-looking tumble into the red dust. He never looked comfortable again.
Nadal pocketed the second set 6-4 and three points into the third set, Djokovic retired with a back injury.
It was Nadal's 58th consecutive win on clay.
-- The Serb then stunned his news conference by insisting "I think I was in control of the match".
"I was playing pretty well. Everything was depending on my racquet. Even with a sore back, I think I played equal.
"I think I could have won today. He's not unbeatable."
Nadal was so baffled by Djokovic's revisionist summary that when he was asked if he thought the Serb was right to state he had controlled proceedings, he demanded the question be translated into Spanish so he could be sure he understood.
"Oh yes," said Nadal, tongue firmly in cheek and to howls of laughter. "If he thinks that, it's OK. I don't need to answer."
TV pundits were stunned.
"Novak, do you need smelling salts?" asked bemused former player and ESPN commentator Brad Gilbert.
"If you want to incite Rafa, the next time you play, he's going to drop the hammer on you. It was heavyweight against middleweight out there."
Gilbert was right. Nadal won all nine of the pair's first claycourt meetings. It took Djokovic until Madrid in 2011 to achieve his maiden victory on the surface against the Spanish star.
Nadal went on to win Roland Garros that year and defended it in 2007 and 2008. He was sinking his teeth into the Coupe des Mousquetaires again in 2010, 2011, 2012, 2013, 2014, 2017, 2018, 2019 and 2020.
Djokovic has lost three Paris finals to Nadal -- in 2012, 2014 and 2020 -- but claimed his first and only Roland Garros title in 2016.
However, he still retains the consolation of being one of only two men to have beaten Nadal at the tournament - in the 2015 quarter-finals.
And what about those 57 meetings? Well, Djokovic currently leads 29-28.