World number one Nadal triumphed in the second consecutive all-Spanish final at the Country club as he won his 12th match of 16 played against his compatriot. He suffered his only Monte Carlo defeat in 2003, his debut year at the venue.
The victory sends Nadal off to his usual solid start of the clay season, with his next challenge his home event next week in Barcelona.
The win marked the 44th career trophy for Spain's top player, who now owns a record 19 titles at the Masters 1000 level and has beaten compatriots in the nine of the all-Spanish finals he has played.
Nadal won a 30th clay court trophy, tying him for third place in the post-1968 Open era with Bjorn Borg and Spain's Manuel Orantes. The victory was revenge for Ferrer's straight-sets win over Nadal in an Australian Open quarter-final three months ago.
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