The 31-year-old, who needs to win an 11th Monaco title to retain the number one ranking ahead of Roger Federer, will face either Kei Nishikori or Alexander Zverev in Sunday’s final.
“Every year is different and equally special,” said Nadal, after beating Dimitrov for the 11th time in 12 meetings.
“So I’ll just focus on doing the things that I have to do to give me another chance tomorrow. That’s it.
“I don’t want to think about another title yet, I just want to think about the way I have to play and try to be ready for it.”
Nadal came through a tight first set but always looked too strong for Dimitrov and raced through the second in half an hour.
The top seed is bidding for an outright record 31st Masters title this week and extended his run of consecutive sets won on clay to 34.
Nadal, playing his first ATP tournament since he retired from his Australian Open quarter-final against Marin Cilic in January with a hip injury, has shown no signs of rust.
Following a 6-0, 6-2 last-eight demolition of Dominic Thiem, Nadal has lost only 16 games in four matches this week.
Dimitrov immediately put Nadal’s serve under pressure with two perfectly-judged lobs forcing deuce, but the top seed came through an eight-minute opener.
Nadal didn’t take long to get into his stride, breaking at the first time of asking as Dimitrov struggled in the longer rallies.
The Bulgarian continued to go for his shots and brought up three break-back points in game five as Nadal followed a double fault with two wayward groundstrokes.
Nadal fired long, before Dimitrov saved a break point himself with a venomous forehand to level at 3-3.
The fourth seed was displaying the resolve needed to push Nadal on his favourite surface, and came back from break point down again as the Spaniard continued to miss chances.
But Dimitrov wasted all of his earlier good work, handing Nadal two set points with back-to-back double faults and a wild forehand.
The 16-time Grand Slam champion wrapped up the set with a whipped forehand onto the line.
That effectively ended Dimitrov’s chances, and Nadal broke to love in the second game of the second set.
Nadal stormed towards the finishing line with eight straight points on his opponent’s serve and a wide Dimitrov backhand wrapped up yet another comfortable victory.