[MLS] Houston's 3-1 defeat of Vancouver Sunday night leaves only Portland and Chivas USA without a victory after four weeks of MLS play.

Expansion entry Portland has yet to play a home game, and few will be surprised if it converts at least one of its home games this week into a victory. An historic opener against Chicago is set for Thursday at Jeld-Wen Field, and FC Dallas comes to town Sunday. The Timbers haven’t played since tying New England, 1-1, at Gillette Stadium April 2.

Home games are part of the problem for Chivas USA, which tied Columbus, 0-0, at Home Depot Center Sunday. It has failed to win in three home games so far this season, and after losing to Sporting Kansas City, 3-2, in its opener, has been shut out by Colorado (1-0) and the Crew. It generated only five shots against Columbus and forced just two saves by Crew keeper Will Hesmer.

Next up for Chivas USA is Vancouver, but the ‘Caps will be at home, where they are unbeaten and have yet to be shut out: Toronto FC (4-2), Sporting Kansas City (3-3), and New England (1-1). They were also shorthanded against the Dynamo, with striker Eric Hassli and midfielder Gershon Koffie suspended and Terry Dunfield sidelined by an injury. Vancouver is also averaging more than 20,000 fans per game.

New head coach Robin Fraser is drastically revamping the team that finished last in the Western Conference last season, so the early-season standings aren’t important. Yet if the Timbers win this week and Chivas USA doesn’t, it will be not only last again, but well behind the two expansion teams in what is shaping up as another wild year in the Western Conference.

The Dynamo, formerly of the West but this year in the East, didn’t respond well to taking a 1-0 lead over the Whitecaps when Cam Weaver scored in the 37th minute; in the next minute, David Chiumiento earned his fourth assist of the season by supplying Camilo for his third goal. Houston did respond to that setback; Bobby Boswell, who had set up Weaver’s goal, beat an offside trap and put away a feed from Danny Cruz shortly before halftime. Will Bruin clinched the victory by evading a charge by keeper Jay Nolly outside the penalty area and rolling the ball into an empty net.