The loss drops the Savage Storm to 12-17 to finish the season. The 12 wins by SE are the most in a season since the 2006-07 campaign.
Zac Downing finished his Southeastern career with a team-best 16 points, but connected on just two three pointers.
He was joined in double figures by Urald King and Antonio Worthy who each posted 11 points.
Worthy showed why he was named the conference Freshman of the Year, adding seven rebounds and a team-high five blocked shots.
The Storm shot 43.9 percent for the game, but saw its second half number dip after hitting 50.0 percent for the first half.
The difference in halves was felt especially from long range where SE saw a 5-for-10 effort in the first half from three-point range turn into a 1-for-10 effort in the second half.
Steven Kohli led the Storm rebounding effort with eight, however Southeastern was out-rebounded on the night by a 39-to-30 margin, with OBU holding a 13-to-8 advantage on the offensive glass.
Chris Roussell dished out a team-high four assists, while Downing and Carliss Robinson each added three.
SE fell behind early, trailing by as many as eight point in the early going of the contest.
The Storm then turned in an 8-0 run that had five points from downing and was capped by a three-point play from Worthy to tie the game at 17-17 with 12:47 to play in the half.
A short 37 seconds later, a Kohli three would drop to put SE in front 20-18.
That lead would grow to 35-28 with 3:34 to play when James Harris hit a three.
The Tigers, however, would finish the half by outscoring the Storm 6-2, leaving SE with a 37-36 lead at the break.
OBU scored the first three points of the second half, but King would answer with a layup to knot the game at 39-39 at the 19:13 mark.
The Tigers would then score the next 15 points to mount a 54-39 lead by the 16”07 mark.
Southeastern would twice cut it back to as close as seven points, the first on a Kohli layup with 13:10 to play and later on a pair of Kohli free throws with 11:17 remaining.
That was as close as the game would get, however as OBU would go on a 17-3 run to push its lead out to 76-55 with 5:05 remaining.
SE would get it back to 17 points on two occasions before the teams settled on the 85-65 final score.