St. Croix has accumulated 302 career points.
Curtis Lazar, with two, Henrik Samuelsson, David Musil and T.J. Foster had the other goals for Edmonton (43-12-5). Laurent Brossoit stopped 20 shots for his fifth shutout of the season and 10th of his WHL career.
Mac Engel made 34 saves for Prince George (18-34-8), which trails the idle Everett Silvertips by three points for the final Western Conference playoff spot.
Samuelsson opened the scoring on the power play at 3:13 of the first. St. Croix drew an assist for his 300th career point.
Lazar converted a loose rebound at 11:49 before St. Croix scored at 10:20 of the second. Musil blasted a wrist shot in from the blue-line with 1:39 left in the period to make it 4-0 Edmonton.
Lazar's short-handed goal at 4:26 of the third and Foster's even-strength tally 14:14 rounded out the scoring.