MLS Eastern Conference pace-setters Toronto FC and the Chicago Fire both won on Saturday night to maintain their momentum.
Jozy Altidore scored Toronto's opener in a 2-0 win over DC United, rounded off by Jordan Hamilton's late header.
The Fire, meanwhile, were 2-1 winners against the New England Revolution with goals from Nemanja Nikolic and Luis Solignac. Antonio Mlinar Delamea's header was not enough to prevent the Revs' first home defeat of 2017.
New York City FC, third in the conference, overturned a 1-0 half-time deficit to beat the Seattle Sounders 2-1. Cristian Roldan's opener was cancelled out by David Villa's brace, the first from the penalty spot.
Jonathan Spector's goal deep into injury time salvaged a 3-3 draw for Orlando City after they appeared to have let all three points slip away against the Montreal Impact. Orlando twice led through first-half goals from Matias Perez Garcia and Carlos Rivas, but Blerim Dzemaili levelled the first time and Ignacio Piatti's brace put Montreal ahead, only for Spector to have the final say with his first Orlando goal.
Sporting Kansas City remain three points clear in the Western Conference after nearest pursuers the Houston Dynamo conceded a dramatic late equaliser to the Los Angeles Galaxy.
Houston also led twice, through Mauro Manotas and Alberth Elis, but Emmanuel Boateng and Romain Alessandrini earned the Galaxy a point, the latter scoring four minutes into stoppage time.
KC, meanwhile, drew 0-0 despite dominating the San Jose Earthquakes.
The Portland Timbers lost 2-1 to the Colorado Rapids, Alan Gordon with the winner after Dominique Badji cancelled out Sebastian Blanco's opener, while FC Dallas and the Vancouver Whitecaps drew 1-1. Cristian Techera's free-kick earned Vancouver a point after Maximiliano Urruti's opener.
Atlanta United beat the Columbus Crew 3-1, Miguel Almiron and Josef Martinez with second-half goals after Hector Villalba's strike was cancelled out by Federico Higuain, while Real Salt Lake beat Minnesota United 1-0 thanks to substitute Yura Movsisyan's 84th-minute goal.