August Falloon got St. Cloud started with a goal at 6:59 of the opening period from Blake Keller.
In the second period, Eric Warner scored from Kyle Christen and Sam Oster at 7:50 and Christian Engel added a goal at 11:09, setup by Jack Randolph and Tanner Simonson.
Keller’s third period goal at 11:39 concluded the scoring with Max Rud and Luke Johnson earning assists.
Christopher Loken came up with 27 saves for the Cardinals as St. Cloud put 31 shots on goal.
Alexandria (13-7) will play at Fergus Falls on Monday night. The Cardinals recorded a 4-2 win over the Otters on December 19 in Alexandria.