Nadal all but hammered in the final nail when he broke after a net-cord pass caught the tape and drew the errant volley, prompting the Swiss to skyrocket a ball out of the stands.
More than two years had passed since one of their greatest tussles and their last in a Grand Slam: the match to decide the 2017 Australian Open.
Federer won that battle from a break down in the fifth.
This, however, was never at risk of going the distance as Nadal closed to within one victory over a remarkable 12th trophy in Paris.
“The semifinals of Roland-Garros is not just another match,” Nadal said. “To have in front probably my biggest rival in my career with all the story that we shared together … that always makes the match a little bit more special and unique.”
Nadal raised his arms victorious for the 24th time against the 37-year-old. Federer raised his arms, too, to applaud his appreciation as he strolled from the court.