In the Patriot League opener for both teams, Alex Woodhouse had 12 points for Colgate (6-8, 1-0), including a free throw with 44 seconds left in regulation that tied the game 65-65 and sent it into overtime.
Colgate scored the first seven points in overtime, four by Kendall Chones and a 3-pointer by Daniel Waddy. Army scored the next six to trail 72-71 with 34.9 seconds remaining.
Colgate's Jon Simon made the second of two free throws with 16 seconds left, and the Raiders went ahead by two. Army's Chris Walker was fouled with two-tenths of a second left, but he missed both free throws.
Colgate led 37-29 at halftime after the Chones brothers combined for 25 points. Army rallied in the second half, tying the score on a 10-2 run.