Canada demonstrated their power early and Hunt blasted over from close range to open the scoring.
Having spoken in the build-up of the need to be clinical with what few chances came their way, Scotland battered at the Canadian line without success.
However, they remained patient and finally engineered an opening for Chloe Rollie to send Lloyd over in the corner.
Canada were unperturbed and went straight down the other end and turned up the pressure. Gallagher was shown a yellow card as the Scots’ defence of their line became increasingly desperate.
Canada then demolished a scrum under the Scottish sticks, the referee adjudged the Scots had halted the momentum illegally and awarded a penalty try.
After a fairly even opening half-hour, the world number two side were starting to move through the gears.
Scotland were struggling to deal with the Canadian speed of ball and Tuttosi finished off a slick move, the Exeter hooker crossing the whitewash in her home ground to give her side a 19-5 lead at the break.
Now playing with a stiff breeze at their backs, the Scots needed the next score to haul themselves back into the match.
They got it after a couple of strong carries from Helen Nelson got them on the front foot before Gallagher ran a brilliant line to slice through the Canada defence and race to the line to score.
The Scots were back within seven points and back in the game but proceeded to shoot themselves in the foot, Tuttosi charging through some soft defence around the fringes to go over for her second try of the match.
Nelson looked to have hit back after gathering the ball at the tail of the line-out and side-stepping to the line but after a TMO review the try was ruled out for offside.
It was a bitter blow and one Scotland would not recover from as Canada marched down the other end and powered over the line through substitute Kassil.
McGhie continued her stunning try-scoring form at this World Cup with her sixth try in three games but replacement prop DeMerchant had the final word as Canada underlined their credentials as one of the tournament favourites.
