Carlos Alcaraz booked his place in his first French Open final after twice coming from a set down to beat Jannik Sinner.
The 21-year-old Spaniard won 2-6 6-3 3-6 6-4 6-3 to become the youngest player to make grand slam finals on all three surfaces; hard-court, grass and the clay of Paris.
Italian Sinner, 22, struggled with cramp during the third set, but still went the distance in a contest lasting four hours and nine minutes.
There may be no Rafael Nadal this year – and this will be the first final not to feature one of the 14-time winner, Novak Djokovic or Roger Federer since 2004 – but Roland Garros could be about to crown a new Spanish champion on Sunday.
Alcaraz, who won both his previous grand slam finals, at the US Open and Wimbledon, said: "You have to find the joy in suffering, that's the key, even more on clay in Roland Garros. Long rallies, four-hour matches, five sets, you have to suffer. But you have to enjoy suffering.
"The toughest matches I've played in my short career have been against Jannik. US Open, this one, and I hope to play many, many more matches like this one against Jannik – but it was one of the toughest matches, for sure."
With Nadal having departed, probably for the final time, and Djokovic's knee giving up on him after the fourth round, Sinner and Alcaraz is the new rivalry this tournament has been crying out for.
It is one that is set to endure, as their latest showdown was the youngest men's singles grand slam semi-final since the 2008 US Open when Andy Murray, then 21, beat a 22-year-old Nadal.
Yet there was little of the intensity of their five hour, five-set marathon at the US Open in 2022, which was won by Alcaraz at 2.50am, as they shared the opening two sets.
The drama came at 2-2 in the third when Sinner, who will be world number one from Monday, began flexing his hands and limping a little, a tell-tale sign that he was cramping up.
Alcaraz had suffered with a similar affliction at the same stage last year, on his way to defeat by Djokovic.
"I saw him struggling a little bit," added Alcaraz. "I was cramping, Jannik as well in the third set. You have to fight. Against Djokovic I was in the same position, but I learnt you have to stay there fighting because the cramp will go away."
Despite two double-faults, Sinner managed a service hold after a lengthy game before receiving treatment at the changeover.
He then somehow conjured up a cross-court service return winner to break Alcaraz and take the third set.
However, two bad Sinner misses while serving at 4-5 in the fourth gave Alcaraz a set point which he took with a blistering cross-court winner.
Alcaraz broke again for 2-0 in the decider and held his nerve up the home straight, taking a third match point before raising both arms in triumph.
For Sinner it was a first defeat in 13 grand slam matches, having won the Australian Open in January, and he admitted it will be hard to watch the final.
"I mean, I always like to watch tennis, yes," he said. "Let's see, if I have time for sure I'm going to watch a little bit.
"But in the other way, it's always tough to watch, especially when you're in the semis, it hurts, because you know that you could be there and it's a different feeling."
