Waiting for him in his 100th ATP final is Gael Monfils, who hammered French compatriot Jo-Wilfried Tsonga 6-1, 6-3, with the loser drawing jeers as he left the court in after 69 minutes.
Monfils, making his second consecutive Monte Carlo semi-final start, never allowed Tsonga a chance in their match, breaking six times.
Nadal will be playing his tenth final here and holds a solid 11-2 record over Monfils. He has not won a Masters title since Madrid, 2014.
“It’s a very important week for me, being in a final here again in Monte Carlo, winning against very tough opponents,” the winner said.
Spain’s fifth-seeded king of clay showed hints of the form which took him to multiple seasons of total dominance on the surface as he overcame second seed Murray in a battle lasting for more than two and a half hours.
“I don’t want to talk every day about if I am back or I am not back. I’m in the final of Monte Carlo. That’s a great news.
“Every year is different. Every feeling is different. I don’t want to compare myself or trying to analyse if I am the same like before or not.
“I want to be today better than yesterday and tomorrow better than today, and after tomorrow better than tomorrow. That’s it. That’s my work today, and that’s my motivation. I don’t want to think about the past.”
It was not all one-way traffic for Nadal, who spent 10 minutes in the final game between his first match points and his fifth in fighting off a late Murray charge.
The 28-year-old Murray saved four match points and had two break chances of his own before Nadal finally drilled over a winner which the Scot could not quite handle.
Murray was unable to maintain his winning momentum after lifting the opening set against the Spaniard who has spent the last 18 months recovering mental confidence after a deep slump.
The 14-time Grand Slam champion has not won a title of any kind since last summer in Hamburg.
Nadal improved to 17-6 over Murray, defeating him seven of the eight times they have met on clay.
Murray will need to step up his pace on clay after winning his first two trophies on the surface last spring in Munich and Madrid back-to-back.
The Scot won the opening set in 49 minutes with a single break, but could not carry on after being broken at the start of the second set.
The second seed got the break back a game later but then lost serve for a second time in the seventh game as Nadal made a winning return off a Murray overhead.
The Spaniard claimed the set after more than an hour as the total match time ticked over to two hours.
Murray’s game went into collapse in the third set as he trailed 5-1 before his futile late rally.