The Panthers (17-10) are making their fourth straight appearance in the championship game. They won in 2014 and 2015, while finishing second last year. LC will face second-seeded Methodist on Saturday at 3 p.m. for the conference's automtic bid to the NCAA Division III national tournament.
Olson led LaGrange with 23 points, 21 coming in the second half; followed by career-highs of 21 points from Thompson and 20 points from McCray. Averett's Jalen Burnett had a game-high 24 points.
The Panthers trailed only twice in the game. They led 41-36 at halftime. The Cougars (12-15) took a brief 44-43 lead three minutes into the second half.
Olson drained a 3-pointer to put LC ahead to stay, 46-44. The Panthers built their lead over the next five minutes. McCray's free throw made it a 10-points game, 60-50.
The Panthers had their biggest lead, 74-59, when Olson completed a three-point play with 6:36 left. LC scored 11 of its final 17 points at the free throw line to seal the win.