Nadal, who will be 25 on Friday, the day of the semi-final, turned in easily his most impressive performance of the tournament, demolishing Robin Soderling 6-4, 6-1, 7-6.
On his side of the draw, Murray charged into the semi-finals for the first time with a 7-6, 7-5, 6-2 win over unseeded Argentinian veteran Juan Ignacio Chela.
He is just the second British player to reach the last four at Paris in the Open era after Tim Henman did so in 2004.
With Roger Federer and Novak Djokovic contesting the other semi-final, it is the first time since the 2006 French Open that the top-ranked seeds are into the last-four in a grand slam event.
Playing a bit like he is still upset about his only loss at Roland Garros to the Swede, Nadal defeated the No 5 seed yesterday to reach the French Open semi-finals for the sixth time.
The five-time champion, who lost to Soderling in the fourth round in 2009 but then defeated him in last year's final, is 43-1 at the clay court grand slam and two wins away from equalling Bjorn Borg's record of six French Open titles.
"I am through. I'm in the semi-finals, so that's the thing," Nadal said.
"I have to be playing better and better every day if I want to have chances to win the final and that's what I'm going to try."
With the wind gusting - at one point blowing specks of red clay into Nadal's face - the Swede struggled with his first serve, landing only 57 per cent during the match.
Nadal, however, did not appear to be bothered by the conditions, although he was broken twice.
The top-ranked Spaniard made only 13 unforced errors, while Soderling had 41.
"Probably, Robin today had a few more mistakes than usual. That maybe helped me a little bit," Nadal said.
"I was lucky for a moment."
Emotionless for almost the entire match, Nadal was able to handle Soderling's hard forehand and kept his opponent on the move by spraying shots to all corners of the court.
And when he smacked a forehand winner to hold serve to 6-5 in the third set, the crowd roared.
After five titles in Paris, Nadal had plenty of fans in the stands, and even some admirers.
Besides the Spanish flags throughout the stadium, one woman held up a sign reading, "Rafa ganador, kiss me por favor" ("Rafa you winner, kiss me please").
Murray, who only completed his five-sets, fourth round win over Victor Troicki 24 hours earlier, again started sluggishly, as he tested out the right ankle he injured against Michael Berrer in the fourth round.
The 31-year-old Chela, who had lost six straight times against the Scot, including in the last two years at Roland Garros, jumped out into a 4-1 lead with two breaks of serve before the fourth seed started to get into his stride.
The 24-year-old Murray saved two sets points to get to 5-4 and then on cue broke Chela's serve again to get level.
The set went to a tie-break, which saw Chela win the first point against serve before Murray went on a run of five straight points to eventually take it 7/2 after which he headed off court for a comfort break.
On the resumption, Murray grabbed another break and he looked totally in control as he smoothly moved 4-1 up with Chela looking for, but not finding, any answers to the Scot's domination.
Inexplicably, serving for the set at 5-2 up, Murray again seemed to lose his focus, allowing Chela to win three games in a row, with two service breaks, to draw level at 5-5.
The Scot buckled down though to take the next two games for a two sets lead.
He then broke Chela yet again to start the third and this time he raced away to victory keeping alive his hopes of finally winning a Grand Slam title after three losing finals.
But to do so he will first have to get past Nadal who he has never beaten on clay.
Friday's other semifinal will be between defending champion Roger Federer and the seemingly unstoppable Novak Djokovic of Serbia.