Seattle Sounders have defeated Colorado Rapids 1-0 at CenturyLink Field to cement their position at the top of the Western Conference.

Joe Nasco was tested early on by the hosts, but he was equal to the strike to deny Seattle a dream start.

Having reached half time level, the Rave Green finally made a breakthrough seven minutes after the restart courtesy of Clint Dempsey's volley.

Nasco was called into action on a couple of occasions shortly after, although neither side could find a second to ensure that Sigi Schmid's charges held out for victory.