A Gaines three-point-play give IPFW a 3-2 lead early in the game; however, the Jaguars (6-10, 1-2 Summit) scored the next eight points to take a seven-point, 10-3 lead.
The Mastodons fought back, tying the score three times in the opening period, but never taking a lead, as the teams went into the locker room knotted at 39.
The margin remained tight in the second half, before IPFW took its first lead since the early goings when Pierre Bland laid in the Mastodons' second straight breakaway lay-up to push ahead 60-59.
The Dons would hold onto that lead, pushing ahead by as many as seven at 68-61 with 8:07 to play after a Gaines jumper gave IPFW the lead.
The lead remained at seven at 70-63 before the Jaguars used a combination of solid defense and a cold IPFW offense which saw the hosts run off a streak of 25-4 over the final seven minutes of the game to claim the win.
IPFW out-rebounded IUPUI 30-to-27, and grabbed 10 offensive rebounds to IUPUI's five. Hines blocked a team-high two shots, as all eight Mastodon players who saw action in the game reached the scoring column.
The Mastodons will travel to Western Illinois on Saturday at 8 p.m.