Claudio Bieler's sixth-minute penalty set the hosts on their way with Soony Saad doubling their lead four minutes before the break and CJ Sapong completing the scoring 10 minutes into the second half.
Seattle Sounders moved to within two points of Western Conference leaders Real Salt Lake after a 2-1 win over Chicago Fire.
Mike Magee put the Fire ahead after 25 minutes only for Lamar Neagle to level five minutes before the break.
The match appeared to be heading for a draw but Chicago's Gonzalo Segares put through his own goal with just a minute remaining.
Los Angeles Galaxy's winning run came to an abrupt end as they lost 1-0 at home to Colorado Rapids.
The Galaxy had tasted victory in their previous four games in all competitions but they were undone by Edson Buddle's 75th-minute strike.
Portland Timbers thrashed Toronto 4-0 with goals from Khalif Alhassan, Rodney Wallace, Will Johnson and Diego Valeri.
Dallas came from behind to beat Vancouver 3-1.
The Whitecaps took a fourth-minute lead through Daigo Kobayashi but that was as good as it got for the Canadians as JeVaughn Watson equalised four minutes later before late goals from Mauro Diaz and Jair Benitez won it for Dallas.