The Billikins (3-1) went on a 12-0 run to erase a nine-point deficit, taking a 48-45 lead on Austin McBroom's 3-pointer off a Reynolds assist with 2:44 to go.
The Aggies (1-4) twice got it back to one but in the final minute Reynolds made 3 of 4 free throws and a layup and McBroom had two free throws. James Whitaker hit a 3 just before the buzzer for N.C. A&T.
Saint Louis went 26 of 34 from the line to 7 of 12 for A&T.
The game was part of the Corpus Christi Coast Classic. Both teams head to Texas for a pair of games this weekend.
It was a Whitaker 3 that put the Aggies up 45-36 with 6:51 to play.
Bruce Beckford had 17 points for the Aggies.