"They were treating it as their World Cup final, they really wanted to get off to a good start to the tournament. We knew they were going to come at us early on and that is what they did," he said.
WRU Audio: Mark Jones looks back at a crucial win over a determined Canada
"That Canadian side put 60 points on the American's that gave England a hard game yesterday so we knew they had the capabilities to score points and put pressure on us and they certainly did that for 45-50 minutes.
"But once we made the substitutions and bought some fresh legs on the game turned.
"Those players had been watching the game from the sidelines and would have seen where the weaknesses were in the Canada defence and when they came on they added to the team."
And Jones said that after a difficult start, it was the way that Wales responded to the third Canada try that particularly pleased him.
"We rode the storm," he said. "It wasn't a perfect start for us: we made a few errors which gave them confidence.
"We might have finished them off a bit earlier had we finished off that movement when they intercepted and scored themselves. That deflated us for 10 minutes but the resolve after they scored early on in the second half was tremendous.
"We stuck to our game plan and believed in what we had been working on throughout the week. We executed our play better and at a far higher intensity in the second half and they found it difficult to live with."
And the wing emphasised the importance of the 30-man playing squad if Wales are to do well in this, the sixth Rugby World Cup.
"It's a squad effort that will make us successful in this world cup and im just pleased to go away with a win and full bonus points."