Nadal reeled off nine straight games against the second-seeded Swiss superstar to seize control, and then closed out the dominating match with a love service game to notch his sixth title of 2013.
Nadal improved to 41-2 all-time on the clay courts of Foro Italico while appearing in his eighth consecutive final since returning from a knee injury in February.
The win gave him more momentum heading into next week's French Open.
Federer fell to 10-20 all-time against Nadal, including 2-13 on clay.
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