Behind the play of 7-foot center Matt Nelson - who scored 10 first-half points - the Rams took a 22-18 lead to intermission.
Air Force's Jacob Burtschi hit a three-pointer 18 seconds into the second half, and after CSU's Sean Morris moved the lead back to four, 25-21 on a three-pointer, Dan Nwaelele hit a trey to close the gap to a point. A minute and a half later, with 17 minutes, four seconds to play in the game, Nwaelele hit another three-pointer to give AFA a 27-25 lead they would never give up.
It was the fifth and final lead change on the night. AFA would continue on a 17-5 run to widen the lead to eight points. Colorado State would come no closer than six points the rest of the way, the last time with four and a half minutes remaining on a pair of free throws by Matt Nelson.
Nelson, finished the game with a team-most 18 points, tying Nwaelele for game honors. Nelson also led all players with eight rebounds. One other Ram, guard Micheal Morris, scored in double figures with 10 points.
Colorado State opened the game by scoring six points - the team's largest lead of the game - on a pair of baskets by freshman forward Jason Smith, and a hoop by Nelson. Smith was returning from a hamstring injury that had sidelined him in the Rams home loss to New Mexico.
The Rams led until just under nine minutes remained in the half when AFA's Tim Keller hit a three-pointer to tie the game at 13, the only tie of the contest.
The teams would exchange four leads during the remainder of the half, CSU regaining the lead with three minutes, 10 seconds left on Nelson's layin, 19-18. Jon Rakiecki's three-pointer to send the Rams to intermission ahead, 22-18.