Colorado Rapids pulled off a 3-1 comeback win over Real Salt Lake, while Seattle Sounders' poor form continued.
Substitutes Charles Eloundou and Juan Edgardo Ramirez turned the game for Colorado Rapids on Saturday, while an early blitz set up New York Red Bulls' third win in four MLS matches.
Eloundou set up all three goals for the Rapids, including one to Ramirez, as Colorado overturned a goal deficit in the final 10 minutes to triumph 3-1 over Real Salt Lake, who finished the match with 10 players.
After spending most of the match in defence, RSL looked on track for a shock win at Dick's Sporting Goods Park in Denver but goals to Drew Moor, Jared Watts and Ramirez saw Colorado prevail at home.
Sebastian Jaime timed his run perfectly to tap Javier Morales' cross into the net in the 79th minute for RSL but just two minutes later Moor levelled the match with a header from Eloundou's corner.
Jaime was then sent off after a scuffle with Moor in the 84th minute before Watts pounced in the first minute of stoppage time to hand the Rapids the advantage, after Eloundou's initial shot came back off the post.
Ramirez wrapped up the hosts' victory in the seventh additional minute, bursting onto Eloundou's pass to run the length of the field and score into an empty net after RSL goalkeeper Jeff Attinella came up for a corner.
The win was Colorado's second in a row but the Rapids remain last in the Western Conference with 21 points, although they moved within two of RSL.
In the East, the Red Bulls drew within nine points of runaway leaders DC United with a 4-1 thumping of New England Revolution.
An early brace for Bradley Wright-Phillips and a goal to Lloyd Sam - all in the opening 12 minutes - saw Red Bulls race away to a 3-0 lead, and although Andy Dorman pulled one back for the visitors in the 37th minute, Anthony Wallace's deflected 25-yard effort settled the match at Red Bull Arena.
Red Bulls could even survive a penalty miss from Sal Zizzo on their way to victory, as Revolution keeper Bobby Shuttleworth pulled off an incredible triple-save in the 89th minute after his captain Jose Goncalves was sent off for conceding the spot-kick.
The poor form of Western Conference leaders Seattle Sounders continued as Sigi Schmid's men lost for the fifth time in six games in all competitions - Chicago Fire stunning them 1-0.
The West's last-placed team triumphed thanks to Jason Johnson's stunning 92nd-minute strike on the counter-attack, while elsewhere, FC Dallas drew level with the Sounders on 32 points thanks to their 2-0 win at Orlando City.
Portland Timbers missed the chance to top the West as they lost 3-0 at Philadelphia Union, while Montreal Impact won by the same scoreline over Columbus Crew.