After the opening minutes, Southern Miss (24-5, 11-3) led the entire game. The win moved The Golden Eagles back into a first-place tie in Conference USA and improved their record at home to 14-0.
Southern Miss used a 15-4 run to finish the first half with a 35-23 advantage and extended to their largest lead at 47-26 early in the second.
Southern Miss allowed FIU (13-16, 5-9) to match its 43 second-half points, but it was good enough to overcome a standout effort from Tymell Murphy.
Murphy had 13 points, 11 rebounds, seven assists, four steals and three blocks for the Golden Panthers.