Delbonis defeated Hyeon Chung 6-4, 6-2 by winning 70 percent of the points on serve. He won 30-of-36 points when he was good on his first serve. Delbonis also saved all three break points he faced while ending up with three breaks.
Mannarino came, away a 6-3, 6-4 winner over Daniel Brands, saving six breaks points in the process. He also won 70 percent of the points when serving, which allowed him to advance with a break in each set.
World No. 4 David Ferrer is the top seed for the tournament. He and the other top four seeds -- Stanislaw Wawrinka, Nicolas Almagro and Jurgen Melzer -- received first-round byes. Juan Monaco won the tournament in 2012 but withdrew from this year's tournament because of a wrist injury.
Swim Week Miami Beach 2014 [PHOTOS]