The second-seeded American needed only 59 minutes to breeze past his French opponent 6-0, 7-6 (9-7), and will next face Croatia's Ivo Karlovic, who got past Canada's Vasek Pospisil 6-4, 1-6, 6-3 Wednesday.
Meanwhile, fourth-seeded Australian Lleyton Hewitt, last year's Newport runner-up, advanced with a 6-2, 6-1 trouncing of India's Prakash Amritraj.
Hewitt goes on to face Czech qualifier Jan Hernych, who moved on with a 6-3, 4-6, 6-4 decision over American Jack Sock.
Also logging Day 3 victories were third-seeded Dutchman Igor Sijsling, Poland's Michal Przysiezny, and Americans Michael Russell and Alex Kuznetsov.
Swim Week Miami Beach 2014 [PHOTOS]