New York City keeper Sean Johnson was the hero but top scorer Valentin Castellanos was sent off late and will miss the Conference finals.
Despite Chicharito's heroics, the LA Galaxy were left emptyhanded on Sunday as RSL spoiled the party in the 95th minute.
Newly-crowned Supporters' Shield winners New England added another accolade with a game to go.
Adam Buksa's 93rd-minute equaliser secured a 2-2 draw for New England Revolution at Orlando City.
Down a goal and a man after 57 minutes, Colorado Rapids rallied to stun Minnesota United.
Philadelphia Union midfielder Alejandro Bedoya called on Congress to protect USA's citizens after a spate of gun violence incident