Gaines' 32 points came on 10-of-18 shooting from the field and 9-of-11 from the charity stripe, as he scored 64 percent of the team's points in the loss. Joe Edwards scored seven, while Pierre Bland added three and Isaiah McCray chipped in three.
Joe Reed pulled down 10 rebounds, as the Mastodons were outrebounded in the game by a 42-to-35 margin. Bland and Reed each dished out three assists, while Bland had a team-best three steals.
The Mastodons (0-1) and Tigers (1-0) went back-and-forth to start the game, with the hosts holding a 4-3 lead just over three minutes into the game, before IPFW rattled off eight straight points to lead 11-4, and would hold onto the lead until late in the game.
The first-half IPFW lead grew to as many as nine at 24-15 with 3:21 to play on one of Gaines' three three-point field goals, before the Tigers closed the half strong, out-scoring IPFW 9-4 over the final three-plus minutes to cut the deficit to four at 27-23.
Auburn outscored IPFW 5-1 to start the second half, knotting the score at 28; however, would not be able to take the lead, as the third of three Gaines free throws pushed IPFW ahead by five at 42-37 with 11:01 to play in the game.
The Mastodon five-point lead would be short-lived, as the Tigers scored the next nine points, including five straight from Frankie Sullivan. The Tigers took a 44-42 lead on a Rob Chubb jumper with 7:04 to play, the first time Auburn had led in the game since the early goings of the contest.
IPFW got back to within two on an Edwards three-pointer with 4:37 to play, but that would be as close as the 'Dons would come, as Auburn answered with a 7-0 run, and closed the game by scoring five straight to give the team its 61-50 win.
The Mastodons hit 15-of-52 shots from the field (28.8 percent), and made just 4-of-20 from long range (20.0 percent) and 16-of-23 (69.6 percent) from the charity stripe. The squad dished out 10 assists while committing 17 turnovers and blocking two shots - both by Reed.
Auburn was led by Sullivan who scored 26 points, while Allen Payne scored 12, and Chubb scored 10 while pulling down a game-high 15 rebounds.
The Mastodons will host Rochester (Mich.) on Tuesday at 8 p.m.