The Vikings couldn't hold on to a 38-36 lead at the half as they shot 24.1 percent in the final 20 minutes in a 78-61 loss to Green Bay Monday night at the Resch Center.
CSU (8-21, 3-13 Horizon League) fell to 6-2 when leading at the half.
Senior forward Vinny Zollo returned from a three game suspension for a violation of team rules and led four Vikings in double-figures with 13 points, all of them came in the first half. Zollo was 5-of-11 from the floor and made three three-pointers.
Kenny Carpenter, Rob Edwards and Andre Yates each added 10 points a piece for the Vikings who dropped its fourth straight.
Carrington Love and Charles Cooper scored 15 points a piece to pace four Phoenix (18-11, 10-6 HL) in double figures. The others were Jamar Hurdle (14) and Jordan Fouse (12).
Green Bay shot 50.9 percent from the field. The Phoenix held a huge edge at the free throw line where they made 16-of-29, while CSU was 11-of-13.
Five minutes into the game, the Vikings fell behind 16-6.
But the next five-plus minutes belonged to CSU. They responded with a 15-4 run to take a 21-20 lead.
CSU pushed the lead out to as much as nine in the first half, but a 12-5 run to close out the half got Green Bay within two at the break.
The Vikings shot 53.6 percent from the floor in the opening half, including 5-of-7 from three-point distance.
Zollo (13), Carpenter (10) and Edwards (8) combined for 31 of CSU's 38 points in the first half. The trio shot a combined 12-of-20 from the floor in the first 20 minutes, including all five of CSU's three-pointers.
But the second half was a different story as the trio struggled, shooting a combined 0-of-10 from the field, for two points - a pair of free throws from Edwards with 4:31 to go when the Vikings were down 17.
The Vikings made its first shot to start the second half, but missed nine of its next 10 as Green Bay started to pull away with a 19-4 run to take a 55-42 lead with 11:58 left to play.
They never got closer then nine the rest of the game as the Phoenix pushed the lead out to as much as 22.
CSU made only seven field goals in the final 20 minutes and were 1-of-13 from three-point distance.