Deep down below the dusty red clay of Chatrier Court at Roland Garros lies a rich seam of mettle and inspiration that only Rafa Nadal seems able to bore into in times of trouble.
More often than not during his seven title runs at the French Open the insatiable Spaniard has not required it.
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On Friday, however, he almost exhausted it completely before beating world number one Novak Djokovic 6-4 3-6 6-1 6-7(3) 9-7 in a semi-final epic lasting four hours and 37 minutes.
There was none of that precious raw material left for Jo-Wilfried Tsonga whose hopes of becoming the first French player to reach the men's singles final here since 1988 ended dismally in a 6-1 7-6 6-2 defeat by Nadal's compatriot David Ferrer.
Tsonga's trouncing of Roger Federer in the quarter-finals had fuelled French hopes but 31-year-old fourth seed Ferrer ground them into the dirt with a ruthless display to reach his first grand slam final after five semi-final defeats.
Ferrer has not lost a set on his way to becoming the oldest man to reach the French final since Andre Gomez in 1990, but faces a gargantuan task trying to stop Nadal becoming the first man to win a single grand slam title eight times.
Only once has Nadal been beaten at Roland Garros in nine years and he proved again on Friday that it will take a super-human effort to prise his hands off the Musketeers' Cup.
Trailing for much of a compelling, almost primal, fifth set, defeat was looming but Nadal dug deeper and deeper to pull away from the brink and claw his way to victory.
"I learned during all my career to enjoy suffering, and these kind of matches are very special," Nadal, who lost a near-six-hour Australian Open final against Djokovic in 2012, said.
"Sometimes I can play and I have the impression I have no limits. This is really important for me."
If he beats Ferrer, over whom he holds a 19-4 record, Nadal will become the most prolific male player at Roland Garros with 59 match wins, one more than Guillermo Vilas and Roger Federer.
All this four months after taking his first tentative steps back on tour after seven months off with a knee injury.
Any lingering doubts about his physical wellbeing were erased in Friday's sinew-twisting win over Djokovic who will be scratching his head at how victory slipped away.
"It's a miracle that he is here after what he went through," uncle and coach Toni told reporters as tears welled in his eyes.
"In the fifth, he is behind but he clings on. In the end, it's in the head that the match is decided."
Serving at 6-5 in the fourth set of a riveting match Nadal seemed poised for an almost routine victory but Djokovic's indomitable warrior spirit saw him break back and then play an exquisite tiebreak to set up a decider.
Fans have over-dosed on classic duels involving any combination of Nadal, Djokovic, Roger Federer and Andy Murray in this golden era for men's tennis and the fifth set alone of this one will be talked about for years to come.
Djokovic had looked flat in the third set which he surrendered in 37 minutes but by the time he ambushed Nadal to win the fourth and move a break ahead in the fifth, the Serb's surgical groundstrokes had Nadal hanging on by his fingernails.
Nadal needed two rip-roaring backhand winners in the fifth game as Djokovic turned the screws in search of the double break that surely would have seen him to the final.
At 4-3 Djokovic still had the match in his hands despite the manic resistance of the man across the net but a surreal eighth game proved the turning point as the match reached boiling point.
Djokovic was warned for taking too long to serve at deuce, then as the point played out he got over-excited as Nadal stretched his frame to retrieve another piledriver forehand but could only slice it high and short.
In rushed Djokovic, and with his eyes bulging he smashed the ball away but tumbled into the net, gifting Nadal the point.
Nadal eventually pounced at the third time of asking to break serve for 4-4 and from then on the 11-times grand slam champion never offered his opponent another opening.
Djokovic requested to have the court watered before coming out to serve to stay in the match for a third time, complaining that the sunshine and breeze had made the baselines slippery.
Nadal was unrelenting, though, and at 7-8 Djokovic's resistance folded. Another bungled smash gave Nadal a sniff of blood and he closed in for the kill, sealing the match on his first match point when a Djokovic forehand sailed long.
"It was an unbelievable match to be part of, but all I can feel now is disappointment," Djokovic, who must try again next year to complete his career slam, told reporters.
"He showed the courage in the right moments and went for his shots. When he was break down in the fifth he made some incredible shots from the baseline. That's why he's a champion."
Tsonga's semi-final had received top-billing, being scheduled for Friday evening prime time.
The only problem was the 28-year-old Frenchman did not turn up as he was completely out-witted by Ferrer.
"It was a bit strange, because there were half of the seats that were empty. This was a bit weird," Tsonga said.
Then again, there was only so much excitement the crowd could handle in one day.