Supporters' Shield leaders Toronto FC extended their MLS winning streak with a derby victory over Montreal Impact, while LA Galaxy were swept aside by San Jose Earthquakes.
Sebastian Giovinco scored twice as MLS pacesetters Toronto defeated the Impact 3-1 on Sunday for their fourth consecutive win.
Former Juventus forward Giovinco broke the deadlock four minutes before half-time, curling a stunning free-kick past Montreal goalkeeper Evan Bush.
Jozy Altidore – named in the United States' squad for CONCACAF World Cup qualifiers against Costa Rica and Honduras – doubled the lead seven minutes into the second half.
Ignacio Piatti reduced the deficit in the 92nd minute but Giovinco restored Toronto's two-goal cushion a minute later as he took his season tally to 15 league goals.
Toronto – top of the Eastern Conference – are nine points clear in the race for the Shield, while the Impact are seventh in the standings and adrift of Atlanta United on goal difference.
It was a day to forget for 10-man Galaxy, who crashed to a 3-0 defeat at home to rivals the Earthquakes.
Substitute Nathan Smith was sent off in the 57th minute after Valeri Qazaishvili put the Earthquakes ahead in first-half stoppage time.
And the floodgates opened as Marco Urena and USA international Chris Wondolowski condemned the lowly Galaxy to a fourth consecutive defeat.
Winless in 10 matches, the Galaxy are second from bottom in the Western Conference, while the Earthquakes are sixth.
Reigning MLS Cup champions Seattle Sounders and Portland Timbers played out a 1-1 draw.