Kyle Beckerman and Robbie Findley scored either side of half-time to give Real Salt Lake a 2-0 win over the Seattle Sounders.
Real went top of the Western Conference and the Supporters' Shield standings on 30 points thanks to Beckerman (41) and Findley (46).
The win stretched Real's unbeaten game to five while the Sounders lost for the second time in 10.
Goals two minutes apart from Dilly Duka and Mike Magee saw the Chicago Fire come from behind to win 2-1 at the Columbus Crew.
Federico Higuain opened the scoring from the spot in the seventh minute, but Duka (52) and Magee (54) turned the match around.
FC Dallas scored twice in the last three minutes to salvage a 2-2 draw against 10-man Sporting Kansas City.
Kei Kamara opened the scoring from the penalty spot two minutes from the break and JeVaughn Watson's own goal in the 58th minute stretched the gap.
The turning point came when CJ Sapong saw red in the 68th minute, and Dallas took advantage as Jackson (88) and Walker Zimmerman (90) netted late on.
Chris Pontius' 11th-minute penalty gave DC United a 1-0 win over the San Jose Earthquakes, while the Houston Dynamo and Toronto FC played out a 0-0 draw.
