Following a scoreless first period the Cardinals took a 2-0 lead on power play goals by Josiah Gronholz and Joe Westlund. Caleb Strong and Matthew Carlsen assisted on the first goal and Gronholz assisted on the Westlund tally.
In the third period, Strong scored from Derek Pesta and Andrew Revering, and Gronholz scored from Brycen Berg.
Alexandria goalie Landyn James earned the shutout, stopping all 12 shots he faced.
The Cardinals (13-6) will host St. Cloud on Thursday night.