Wales suffered a second Women's Rugby World Cup defeat as Canada won a bruising contest 15-0 at Billings Park in Dublin.
Having lost their opening game to New Zealand 44-12, Wales knew they would have to upset the 2014 World Cup runners-up to make any real impact in Group A.
Wales kept within one score of Canada until the final 11 minutes, but the game eventually hinged on two yellow cards in the last quarter.
Canada were reduced to 14 women when Julianne Zussman stamped on Wales replacement Meg York 17 minutes from time.
At that stage Wales were only seven points adrift, but their numerical advantage lasted just three minutes.
Wales were punished at the breakdown and referee Sean Gallagher sent captain Carys Phillips to the sin bin.
Canada dominated the early exchanges, but Wales' defensive line held firm until the 25th minute when scrum-half Lori Josephson broke away.
Magali Harvey added the conversion and the winger almost extended Canada's lead at the start of the second half but was dragged down close to the line.
Wales struggled to find a real attacking threat, but they were handed an opportunity to get back in the game when full-back Zussman was correctly carded for indiscipline.
But Phillips soon followed her out of the action and Canada landed a decisive blow as Hannah Jones was penalised for not rolling away and Harvey dispatched a 22-metre penalty.
Canada's victory was secured in stoppage time when Harvey was freed by a quick penalty and she sprinted down the right wing for her sixth try of the tournament.
After beating Hong Kong 98-0 in their opening game, Canada have yet to concede in the World Cup.
They now face New Zealand in their final game to determine the winner of Pool A.