Real Salt Lake missed the chance to replace the San Jose Earthquakes atop the Major League Soccer Western Conference after slumping to a 1-0 defeat at Colorado Rapids.
With San Jose not in action, Real Salt Lake could have gone a point clear at the summit with a victory, but instead they slumped to an eighth defeat of the campaign after going down to a 38th-minute Nane Joseph goal.
In the Eastern Conference, Sporting Kansas City leap-frogged above the New York Red Bulls and joined leaders Houston Dynamo on 40 points with a 1-0 win at New England Revolution.
Teal Bunbury's 20th-minute strike was the difference between the sides as Sporting picked up their first win in four MLS matches.
In the same conference, DC United, Chicago Fire and Montreal Impact were all celebrating victories.
Fourth-placed DC United beat Columbus Crew 1-0 through a 50th-minute goal from Chris Pontius while Chicago recovered from a half-time deficit to beat Toronto FC 2-1.
Bottom side Toronto took a 15th-minute lead through Ryan Johnson but Chicago equalised through Marco Pappa's 64th-minute strike and then, soon after Toronto had lost Logan Emory to a red card, they snatched a winner thanks to Austin Berry's 84th-minute effort.
Montreal's 2-0 win over Philadelphia Union was secured with goals from Andrew Wenger (44) and Felipe Martins (80). Both teams finished with 10 men after Montreal's Nelson Rivas and Jack McInerney of Philadelphia were handed red cards in the 69th minute.