Los Angeles Galaxy coach Bruce Arena lashed out at officials on Saturday after his side surrendered a goal in the 95th minute to lose 1-0 to the Colorado Rapids.

"That's a 93-minute game at the most and to lose in the 95th minute is a crime," Arena told reporters after Marco Pappa's strike gave the home side the win.

"It's disgraceful, it really is ... Bad judgment by the fourth official not to question it."

The goal came after Galaxy defender Daniel Steres' attempted clearance fell straight to Pappa.

"Just a bad clearance spun off my head, fell right to their guy and quite a finish," Steres said. "We were just trying to bunker down and see out the end of the game."

Match-winner Pappa, who was the victim of a stabbing in December, savoured the win and said he was trying to move on from the incident.

"Nobody likes to talk about the bad things that happen in your life," Pappa said, adding that he was focused on his football and family.

In Montreal, Ignacio Piatti netted his third goal of the season to lead the Impact to a 3-0 win over New York Red Bulls.

Dominic Oduro and Anthony Jackson-Hamel also netted for Montreal.

"We need everybody, and we all came out here to play," Oduro said. "That's what's important right now. We have momentum from last year, and it's really positive. We're playing well, with help from Mauro (Biello) and his coaching staff."  

Dominic Dwyer hit a pair of goals as Sporting Kansas City maintained their perfect start to the season with a 2-1 win over the Vancouver Whitecaps.

Dwyer scored both of his goals before the break before Pedro Morales pulled one back from the spot for Vancouver, but they are still searching for their first win of the season.

Houston Dynamo picked up their first win of the season as they coasted to a 5-0 victory over FC Dallas.

David Horst opened the scoring before Matt Hedges turned the ball into his own net and further strikes from Ricardo Clark, Andrew Wenger and Will Bruin wrapped it up.

Jamison Olave's header four minutes from time gave Real Salt Lake a 2-1 win over the Seattle Sounders, while Chris Pontius scored twice as the Philadelphia Union overcame the Columbus Crew 2-1.