The second-ranked Nadal has been nursing a sore shoulder since the end of last season and lost to David Ferrer in the semifinals on Friday, but looked back to his old self against Federer. He took a 3-0 lead in the first and was never seriously threatened by his Swiss rival, who was routed by Novak Djokovic in the semifinals.
Nadal clinched the win with a blistering forehand into the corner.
Djokovic faces Ferrer in the final later Saturday.
The $250,000 winner-takes-all six-man tournament is a warm-up for the new ATP season which begins next week.
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