Safin, a Moscow native, lost his first set but was solid in the other two for a 3-6, 6-1, 6-4 triumph over Italy's Daniele Bracciali. Safin earned a Friday quarterfinal pairing against Serbia's Janko Tipsarevic, who was a 6-4, 6-4 winner over the Czech Republic's Robin Vik on Thursday.
Sixth-seeded Frenchman Julien Benneteau was upset by Belarusian Max Mirnyi 6-2, 2-6 7-6 (7-2). Mirnyi moves into a quarterfinal match with top-seeded Russian Nikolay Davydenko.
The only other seeded play who had a match Thursday was No. 7 Frenchman Fabrice Santoro, who ousted Russian qualifier Konstantin Kravchuk 6-1, 6-1. Other second-round winners were German Philipp Kohlschreiber and Frenchman Arnaud Clement.
The tournament is scheduled to wrap-up Sunday with the titlist winning $142,000.
Swim Week Miami Beach 2014 [PHOTOS]