Three were dispatched most notably when the world number one was serving at 4-4.
He eventually edged 5-4 ahead and capitalised on his second break point when Del Potro was serving to make it 5-5.
Once the Argentine was broken at the start of the second set, despite the exhortations of a packed centre court, the future looked gloomy for the 29-year-old. He lost it 6-1 and had few answers for the Spaniard’s voom and variety in the third set. Nadal took it 6-2.
“I think that was my chance of the match,” rued Del Potro. “I had a lot of break points. I couldn't make it. Rafa served well, played good points on those break points and I got unlucky in that moment. It could have been a different match if I’d won the first set.”
That could be wishful thinking. Nadal lost the first set in the quarter-final against the 11th seed Diego Schwartzman and eventually pulverised Del Potro’s compatriot.
But while Nadal complained about his initial passivity in that last eight encounter, he was gracious enough to hail his good fortune in the meeting with Del Potro.
“Of course with 0-40 and 15-40, normal thing, at minimum, you lose one of these two games, but today was not that case. I feel a little bit lucky for that,” said Nadal. “For me, the only way to approach these moments is just think point by point, just try to think about how to win the point of 0-40, then the 15-40. And then when you are 30-40, you know that you are close to save it. Because if you come back to deuce, the chances are better for you than for the opponent.”
With his iron will palpable, he dissected the willing but increasingly important Del Potro. “He's too strong,” added Del Potro. “He has improved his backhand a lot. That's why he's the number one and beating all the guys. He looks fresh. And the strength that he has and the mentality. It works perfect for him playing in clay.”
Such an assessment will offer bleak reading for Dominic Thiem, Nadal’s opponent in the men’s showdown on Sunday. The 24-year-old Austrian advanced to his first Grand Slam final after extinguishing the resistance of the unseeded Italian Marco Cecchinato in straight sets 7-5 7-6 6-1.
It could have been a tad more taxing for the seventh seed. He became embroiled in a tense tiebreak after having three set points at 6-3. He squandered them with two poor volleys and a sloppy forehand. Cecchinato had three opportunities to level at one set all before Thiem seized control of the match on his fifth set point.
“Obviously he felt all the matches from these two weeks after he lost that second set,” said Thiem. “If he had won the tiebreak, he would have been full power, for sure, in the third set. So it was good for me that I won it.”
Thiem is the only man to have beaten Nadal in his four clay court tournaments this season. That was in the last eight at Madrid. In 2017, he overcame Nadal at the Italian Open. However he has lost both of his meetings with Nadal at Roland Garros.
“For sure I can take some things from those victories. If I want to beat him, I have to play that way like I did in Rome and in Madrid. But I'm also aware that here in Paris it's tougher. He likes the conditions more here than in Madrid. Best of five is also different story.”