Phoenix's free throws gave the Blue Devils (1-8) an 81-76 lead with six seconds left. The River Hawks' Isaac White made a 3-pointer and Austin Nehls added another pair of foul shots to cap the scoring. Nehls finished with 20 points and eight boards.
Phoenix got his first start in an 82-57 loss to Boston College on Nov. 19 when the freshman played only 11 minutes. Phoenix had 23 career points entering Friday night's game.
After CCSU took the lead for good at 62-60 on Phoenix's layup with 8:50 left, UMass-Lowell (4-6) trailed by no more than five and closed back within two seven times.
Matt Harris had 15 points to lead five Mountain Hawks in double figures.