Nadal has reasserted his dominance on clay this season
Rafael Nadal beat fellow Spaniard David Ferrer 7-5 6-2 to equal Andre Agassi's record of 17 Masters titles in a rain-delayed final in Rome.
Ferrer saved five break points in the early stages but Nadal emerged after a rain delay to break the world number 17's serve late on and edge the opener.
A second downpour followed when Nadal was a break up in the second at 2-1.
But neither the weather nor Ferrer could avert Nadal's march to a fifth Rome title in six years.
American Agassi's Masters Series record came at the age of 34, while Nadal has achieved the same feat at just 23.
I'm probably more happy winning without playing my best. It was more of a mental thing
"It's important to have the motivation to want to keep improving. That's the main thing," Nadal said.
"That's how it's been all my career, all my life, and I still do it. I love to play tennis."
It was a tough day for Ferrer, who came under early pressure when he fended off five break points at 2-2 with some brave winners into the corners.
Ferrer continued to hold his own before the action was suspended for an hour with the pair deadlocked at 4-4.
When the players re-emerged, the next two games went with serve but Nadal broke his compatriot in the 11th when a Ferrer forehand clipped the top of the net at the end of another arduous rally.
A break point for Ferrer in the next game proved a mere inconvenience for Nadal as he fended off the danger with a powerful wide serve that his opponent returned long.
A similar exchange gave Nadal the set, and just after he had broken again in the third game of the second set another rain delay - this time lasting one hour and 45 minutes - sent many of the 10,000 crowd home.
Those who did stay saw Ferrer gift Nadal another break with a double fault and a loose forehand wide before the six-time Grand Slam winner served out for a fifth Rome title.
And ominously for his rivals at the French Open, which gets under way on 23 May, Nadal is unbeaten in 10 clay-court encounters this year.
He ended an 11-month title drought at the Monte Carlo Masters two weeks ago and dropped only one set in Italy this week - that blip coming during a three-set semi-final victory over unseeded Latvian Ernests Gulbis, world number one Roger Federer's conqueror in the second round, on Saturday.
"I didn't play at the level I did in Monte Carlo but I'm still winning and that's the important thing," Nadal said.
"I'm probably more happy winning without playing my best. It was more of a mental thing."
And after a series of knee problems over the last year, Nadal was happy to report: "I didn't have any problems with my knee and that's an important thing."
Ferrer, meanwhile, speculated that the rain had affected his chances but was pleased with his form overall.
"Maybe the court was slower and I had problems to end the points," he said.
"Of course Rafael had good chances in the important moments. It's difficult against him but I'm happy with my game."