FAU rallied from 12 points down and closed to 76-74 on Michael Forrest's 3 with 16 seconds left and Brian Beard Jr. missed a pair of free throws at the other end. But Xavian Stapleton missed a layup with four seconds left and Antonio Daye Jr. iced it with two from the line.
Beard had 14 points and nine assists and Daye added 10 points and seven assists for the Golden Panthers (13-7, 4-3 Conference USA), who held the Owls to 38-percent shooting but were outrebounded 50-32.
FIU pulled ahead late in the first half on Willy Nunez Jr.'s 3 and led 40-34 at halftime.
Adger scored 21, Richardson Maitre added 15 and Stapleton had 13 with nine rebounds for FAU (11-9, 2-5), who have lost four straight.
The teams play again Saturday in Miami.
Illinois' Alan Griffin suspended 2 games for stepping on opponent
Illinois guard Alan Griffin received a two-game suspension for stepping on Purdue's Sasha Stefanovic during Tuesday's game.
No. 13 Butler out to contain Marquette's Howard
No. 13 Butler will look to snap a three-game losing streak when it hosts Marquette on Friday in Indianapolis.
Four North Carolina signees dot McDonald's All American Game rosters
The nation's top two committed players -- Evan Mobley (No. 2, USC) and Cade Cunningham (No. 3, Oklahoma State) -- will be on opposing teams at the McDonald's All American Game.