Sporting Kansas City established a four-point advantage at the summit of the MLS Eastern Conference with a 2-1 win over Toronto FC.
Ryan Johnson fired visiting Toronto ahead in the 44th minute but Paulo Nagamura levelled for Sporting before substitute Oriol Rosell hit the winner for the host in the 87th minute.
Real Salt Lake closed to within four points of Western Conference leader San Jose Earthquakes with a 1-0 win over DC United thanks to Will Johnson's 49th-minute effort.
Substitute Emilio Renteria hit a last-minute winner to lift Columbus Crew to a 2-1 win over Montreal Impact.
Marco Di Vaio fired the Canadian side ahead in the 73rd minute, but Chad Marshall (80') levelled for the host before Renteria found a dramatic late winner.
David Beckham scored a trademark free-kick and Juninho was also on target as Los Angeles Galaxy ran out a 2-0 winner over Vancouver Whitecaps, while the match between New England Revolution and Philadelphia Union ended goalless.