Nadal won two-thirds of the points in a 6-1, 6-1 romp over Daniel Gimeno-Traver. Nadal didn't face a break point and finished off five of his nine break-point opportunities.
Ivan Dodig fought off seven of nine break-point situations in posting a 6-2, 6-4 victory over third-seeded Robin Soderling but No. 4-seeded David Ferrer was a 6-2, 6-2 winner over Carlos Berlocq.
No. 6-seeded Jurgen Melzer also moved into the third round, topping Marcel Granollers 6-1, 6-3 and ninth-seeded Richard Gasquet used a strong third-set showing to claim a 6-3, 4-6, 6-2 win over Blaz Kavcic.
Also, No. 11-seeded Albert Montanes outlasted Benoit Paire 6-7 (3-7), 6-1, 6-4 and 15th-seeded Milos Raonic survived a third-set tiebreaker in beating Simon Greul.
A trio of seeded players joined Soderling as upset victims. Feliciano Lopez ousted 12th-seeded Guillermo Garcia-Lopez 6-7 (2-7), 6-3, 6-4; Victor Hanescu defeated No. 14-seeded Kevin Anderson 6-4, 6-4; and qualifier Simone Vagnozzi beat 16th-seeded Juan Monaco 6-3, 6-3.
Other winners Wednesday were Santiago Giraldo, Kei Nishikori, Nikolay Davydenko and Juan Carlos Ferrero.
Swim Week Miami Beach 2014 [PHOTOS]