Two goals apiece from Steven Lenhart and Chris Wondolowski helped the Western Conference-leading San Jose Earthquakes to a 5-3 win over DC United.
Dwayne De Rosario put United ahead after eight minutes, but the Earthquakes stormed back through goals from Lenhart, Wondolowski and Justin Morrow to lead 3-1 at half-time.
Dan Woolard pulled one back in the 64th minute, but another goal apiece from Wondolowski and Lenhart killed off the game before Hamdi Salihi made it 5-3 two minutes from the end.
The result was also good news for Kansas City, who lead the Eastern Conference now by six points from DC with two games in hand.
Goals either side of half-time from Eddie Johnson and Freddy Montero gave the Seattle Sounders a 2-0 win over the Los Angeles Galaxy.
Saer Sene and Fernando Cardenas scored to lead the New England Revolution to a 2-1 comeback win over Colorado after Jaime Castrillon had put the Rapids ahead.