VANCOUVER, June 18 : Jonathan David bagged a hat-trick as Canada demolished nine-man Qatar 6-0 on Thursday to secure their first win at a World Cup finals and lift the co-hosts ahead of Switzerland at the top of Group B.The win came at a price, however, as Canadian midfielder Ismael Kone was carried off the pitch with an inflatable red boot on his left leg after a challenge by Assim Madibo early in the second half that earned him a red card and reduced Qatar to nine men.Cyle Larin pounced on a rebound to open the scoring before David fired home a volley and then converted from close range. Nathan Saliba put the game out of reach when he drilled home a free kick shortly after entering the game for Kone, an own goal from Mohamed Manai made it 5-0 and David completed his treble in stoppage time with a left-foot shot.Qatar were reduced to 10 men in the 34th minute when Homam Ahmed was sent off for a foul on Tajon Buchanan that originally led to a penalty being awarded until a review determined the challenge was just outside the area.Canada joined Switzerland on four points through two matches but lead Group B on goal difference. Canada close out the group stage against Switzerland on June 24 in Vancouver while Qatar face Bosnia and Herzegovina in Seattle.