Diego Valeri set an MLS record in a surprise Portland Timbers loss, while Josef Martinez struck another hat-trick for Atlanta United.
Valeri scored for the eighth consecutive game - an MLS record - as the Timbers were edged 2-1 by Real Salt Lake on Saturday.
Albert Rusnak opened the scoring for hosts RSL in stunning fashion, his 25-yard effort beating Jeff Attinella in the 14th minute.
But Valeri broke the MLS record and equalised just after half-time, heading in a fine Dairon Asprilla cross.
However, Jefferson Savarino scored a brilliant winner for the hosts, ending the Timbers' four-match unbeaten run.
Portland also missed a chance to go above the Vancouver Whitecaps, the Western Conference leaders having been held to a 2-2 draw at home to Columbus Crew.
Only one point separates the top four teams in the conference.
Sporting Kansas City are third after a 3-1 win over the New England Revolution, while the fourth-placed Seattle Sounders drew 0-0 at Dallas.
Meanwhile, there was also history made in Atlanta as an MLS record crowd of 70,425 watched United draw 3-3 against Orlando City.
Dom Dwyer headed in the opener for Orlando before Martinez tapped in an equaliser.
Another Dwyer header restored Orlando's lead, but again Martinez levelled with a header of his own.
A header from Cyle Larin put the visitors ahead once more, only for Martinez to tuck away his second hat-trick in as many games.
Atlanta are fifth in the Eastern Conference, which is topped by the red-hot Toronto.
Tosaint Ricketts scored a brace in Toronto's sixth straight win, a 4-0 thrashing of LA Galaxy.
Elsewhere, Minnesota United beat Montreal Impact 3-2 and Chicago Fire were too good for DC United 3-0.
The Colorado Rapids and New York City drew 1-1, while the San Jose Earthquakes edged Houston Dynamo 1-0.