The Colonials, 9-2, trailed 34-26 with 3:08 remaining in the first half before going on a 20-9 run over the next seven minutes to take a 46-45 lead at the 16:25 mark.
Keene State, now 7-5 overall and 2-2 in the league, took its last lead 20 second later, 47-46. That would be the last time it would be in front as WestConn 17 of the next 21 points to build a 12-point lead, 63-51 with 8:53 left in the game.
Senior forward Brice Assie (Bridgeport, CT), who had a double-double by intermission, finished with a game-high 21 points, 13 rebounds and five blocks for the Colonials.
Jay Reginatto (Torrington, CT) added 12 points, nine of which came in the second stanza.
Sean Sullivan (Athol, MA) led the Owls with 13 points while Ben Maynard (Nobleboro, ME) and Harley Davis (Newburyport, MA) chipped a dozen points apiece.