Belgium "need to improve" if they are to stand a realistic chance of going deep at the 2022 World Cup, according to defender Toby Alderweireld.
It was Alderweireld's long pass that created the only goal of the game for Michy Batshuayi as Belgium struggled to make much headway against an athletic and well-drilled Canada team.
Alphonso Davies saw an early penalty saved by Red Devils goalkeeper Thibaut Courtois and Canada also squandered a host of first-half chances as Belgium held on to a precious win to take an early lead at the top of Group F.
Alderweireld said: "We didn't play our best game, but we fought hard, especially in the second half and it's better to improve things with three points in the bag than no points.
"We weren't good enough on the ball, we didn't create the right spaces and in the second half we could have hurt them a lot more. Our last pass has to be a lot better.
"The first step is to get through but we need to improve."
Alderweireld's sentiments were shared by fellow defender Timothy Castagne, who felt Canada's no-fear approach made them tricky opponents.
The Leicester City full-back said: "We were expecting that, it's not easy to play against.
"We tried to play through them but we could not find the free men. When we did, we had some good opportunities but couldn't finish them.
"We can thank Thibaut for keeping us in the game first half. After that we defended pretty strong together, which hasn't always been our strongest suit so that's good."
With Argentina and Germany having already lost in Qatar to unheralded opponents, Castagne was just pleased Belgium avoided joining the ranks of beaten favourites, adding: "If you get the win, you get confidence even if it wasn't our best game.
"Some big teams have lost so it's good to get off to a good start points-wise."
While Belgium were relieved, it was a night of pride and frustration for Canada. They emerged with enormous credit, inspired by the shrewd leadership of head coach John Herdman, but will rue their profligacy in front of goal.
Defender Steven Vitoria said: "We deserved more against a world-class side. When we play like that we'll be a lot closer to winning than anything else. It was a fantastic performance but at this level you have to get the win.
"The intention is to be fearless on the biggest stage, this is a new Canada and we gave that statement to the world. But no excuses, we're here to win and we're not satisfied."