Gordon McRorie did all the scoring for Canada 'A' as he kicked three separate penalty goals — all in the first half.
The 26-year-old scrum-half put Canada 'A' up 3-0 early with a penalty before the Jaguars responded with a try and penalty of its own to lead 10-3.
McRorie, who is from Scotland but resides in Calgary, hit on two more penalties to make it 10-9. Argentina, however, tacked on three more points before halftime for a 13-9 edge.
The second half was all Jaguars as they put up 26 unanswered points en route to their third straight win of the tournament.
McRorie finished the three-game championship as the top scorer for Canada 'A' with 22 points.
Earlier in the day, the United States hammered Uruguay 30-5 to finish with a 2-1 record. Uruguay finished the competition winless while Canada 'A' went 1-2.