MLS’s Champions League campaign is heading toward ruin again.

The Los Angeles Galaxy wasted a terrific build-up and goal in the first half by conceding two late goals from close distance in a 2-1 loss to Monterrey in the first leg of a CONCACAF semifinal series Wednesday at Home Depot Center.

A.J. DeLaGarza scored for the Galaxy, but Chilean forward Humberto Suazo equalized in the 82nd minute and Aldo De Nigris struck as 90 minutes expired for a stunning advantage heading into the second leg in Mexico next week. Both the Galaxy and Seattle Sounders (who are trailing Santos Laguna 1-0 after a home loss Tuesday) face tall tasks in pursuit of championship berths.

The L.A. goal:

Monterrey’s equalizer:

Monterrey’s game-winner: