Toronto FC tied up the MLS Supporters' Shield with a 4-2 win over the New York Red Bulls.
The Canadian side sit nine points clear of second-placed New York City FC with only two matches left to play before the post-season begins at the end of the month.
Toronto took the lead on 31 minutes when the visitors failed to clear and Justin Morrow scored a scrappy goal, and he went on to double the advantage minutes later.
Gonzalo Veron pulled the Red Bulls back to 2-1 before half-time, and Daniel Royer slotted home a penalty in the 76th minute to tie things up.
Victor Vazquez scored a penalty for Toronto in the 80th minute before Morrow sealed his hat-trick, and the win for Toronto, in stoppage time.
Columbus Crew sealed a spot in the play-offs with a 2-0 win against DC United thanks to Josh Williams and Justin Meram goals either side of half-time, while the Vancouver Whitecaps also made it through to the post-season with a 1-0 win over Sporting Kansas City.
Honours were even between Atlanta United and the New England Revolution, who drew 0-0, while New York City FC and the Chicago Fire drew 1-1 with Nemanja Nikolic's opener cancelled out by a strike from David Villa.
FC Dallas and Orlando City played out a 0-0 draw, while the Houston Dynamo scored two in the second half through Alberth Elis and Romell Quioto to beat Minnesota United 2-1.
The Colorado Rapids played nearly 80 minutes with 10 men after Jared Watts was given his marching orders, but Montreal Impact lost the man-advantage in the 32nd minute. Alan Gordon nabbed the winner in the 81st minute in a 2-1 win for Colorado.
Kyle Beckerman scored a 95th-minute equaliser as his Real Salt Lake side drew 1-1 with LA Galaxy, while the San Jose Earthquakes beat the Portland Timbers 2-1.