Tennis's version of the immovable object against the irresistible force enters its 43rd chapter today as Rafael Nadal takes on Novak Djokovic for the French Open title.
World No 1 Nadal will be looking to win a record-extending ninth Roland Garros crown while No 2 Djokovic will attempt to become only the eighth man to win all four Grand Slam events.
Throw in the fact that the winner will also claim the world No 1 ranking going into Wimbledon and you have a melting pot that could produce a classic.
Loading article content
For Nadal, it is about extending his record in Paris to 65-1, his only loss coming to Robin Soderling in 2009 when his troublesome knees were creaking badly.
Since then, no matter what form he has been in coming into the tournament, the Spaniard has managed to turn it on when it gets to the business end.
This year, he won just one of the European clay-court events, his worst effort since 2004, but against Andy Murray in the semi-finals, he motored into top gear.
However, even Nadal, with his imperious record in Paris, knows Djokovic represents another step up in class, his toughest challenge, especially on clay.
The big question is how the two will handle the pressure; for Nadal it is about remaining King of Clay; for Djokovic, ending his rival's reign and joining an elite band to have won the sport's four majors.
"Novak has already had positive results here and it's nothing new for him to be in the final," Nadal said. "He has the motivation to win Roland Garros for the first time, for sure. But at the same time he has the pressure to win for the first time. I have the pressure that I want to win and the motivation that I want to win my ninth title.
"I don't see a big difference in that. I'm going to go on court with the same motivation as him. I don't know if it's the same pressure. Probably we are in different situations, but I don't know if that's going to make a big impact on the match. What's going to make the real impact is which player is playing better."
Djokovic has won their past four battles, including in the final in Rome last month, but Nadal has won their past three matches in Grand Slams, including here last year when the Serb led by a break at 4-3 in the final set but could not see the match home.
On form, Djokovic should be the favourite but the manner of Nadal's win over Murray and the Serb's slightly up-and-down win over Ernests Gulbis in his semi-finals means the bookmakers have given the Spaniard the edge again.
Djokovic said he expects to handle the pressure better than he has done here in the past.
"It is more of a motivation for me, more of a positive emotion going into the finals," he said. "Of course the pressure is there. Expectations are there. They are always present when you are playing at this level. But I'm trying to channel this energy into the right direction and not get carried away too much by the stress of the occasion.
"It is the final. It is the final of a Grand Slam I have never won. I'm going to have the ultimate challenge on clay across the net in Nadal. We all know how successful he is. But I have to believe and I have to try to win it."
The dynamic between the two is likely to be the same as on most of the 42 other occasions they have met; Djokovic trying to attack, Nadal defending and then turning defence into attack whenever he has the chance. Should Nadal dominate the rallies, Djokovic knows he will be in trouble, so the Serb will be desperate to be getting the first strike and maintaining court position from there. "I'm going to try to be aggressive, because that is the only way I can win against him," Djokovic said.
"I know, of course, that this is the court he's most dominant on. This is where he plays his best. It's a very wide and very big court. He likes to have that visual effect, as well, because it appears that he gets every ball back. He feels more comfortable when he plays on the bigger court. That's one of the reasons why he's so successful here.
"But knowing I was so close to beating him the past two years gives me that reason to believe that I can make it this time.
"I'm going to try to stay with my own tactics. I know what I need to do in order to win. It's easier said than done, of course, but he's not unbeatable. Winning against him in the last couple of matches in finals of big events definitely gives me confidence that I can do it again."