Canada, ranked 70th in the world, came into the game as an underdog against the 11th-ranked Mexicans, who have treated the Gold Cup like their own over the years.
The contest was paused in the dying minutes of regulation time because of offensive chants from some quarters of the sellout crowd at NRG Stadium.
Qatar, host of the 2022 World Cup, was a guest entry in the championship of the region covering North and Central America and the Caribbean.
Seconds later, Edson Alvarez chopped down Canada’s Richie Laryea in front of the players bench and a full-blooded melee ensued with players from both sides getting involved.
Salcedo and the Mexicans had hoped the offside flag would go up but it stayed down as the 22-year-olf Buchanan celebrated his first senior goal for Canada in nine appearances.
The Canadian men were hoping to reach the final for the first time since 2000 when they won the tournament, dispatching Mexico along the way.
Canada was without Alphonso Davies, Jonathan David, Atiba Hutchinson, Milan Borjan and Scott Arfield, who were injured or unavailable.
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