CARSON, Calif -- This afternoon will see day four of CONCACAF Olympic Qualifying at The Home Depot Center in Carson, but there's been a major upset as the United States U-23 team was defeated 2-0 by Canada last night at LP Field in Nashville. Mexico take on Honduras tonight in Carson, and are expected to finish top of Group B.

Mexico won their first match against Trinadad and Tobago 7-1 on Friday night, getting a hat trick from Marco Fabian of CD Guadalajara. Defender Israel Jimenez of Tigres UNAL also scored on a night when goals came cheap. Honduras won their match 3-1 earlier that day, and will likely be Mexico's toughest match of the Group. A decision tonight will all but clinch Group A for the victor.

The US were expected to finish top of Group A, but now have to defeat El Salvador in their final group stage match tomorrow. Canada got goals from Doneil Henry of Toronto FC and Lucas Cavallini, both in the second half. Canada now has 4 points to the US 3, and face Cuba in their last match; a team the US defeated 6-0.

The runner up of Group A will face the winner of Group B in the Semi-Finals at Livestrong Park with the winner moving on to the Olympics. This means a US vs. Mexico Semi-Final for an Olympic spot is not only possible, but it's now the most likely way forward.