The Canadians, who play Ireland in Limerick this weekend, had full back James Pritchard to thank for 16 of their points as he crossed for the second of their tries and added a conversion and three penalty goals with the boot.
The first half Canadian try was scored by flanker Adam Kleeberger but Portugal never let the visitors relax and, while Canadian coach Kieran Crowley expressed his satisfaction with the win, he admitted frustration at the lack of possession and territory in the second half.
“Portugal really took it to us in the second half – and we really didn’t have that many opportunties,” he said. “I think our defense was great and really kept Portugal out of the game, but we needed the ball more if we wanted to really open the match up so Portugal did well in that respect.
“I think we need to really focus on the positives but we need to look at the video and make the adjustments and put in some hard work this week ahead of the Ireland match.”