Western Conference leaders Sporting Kansas City were upstaged by Houston Dynamo 2-1 in MLS, while Vancouver Whitecaps stunned Toronto.
Houston routed Sporting KC 5-2 in August and Dynamo claimed another win over their rivals in the west on Saturday.
After a short weather delay at BBVA Stadium, Dynamo came from behind following Erik Hurtado's 30th-minute opener in Houston.
Within a minute of his introduction, Alberth Elis equalised for Houston in the 59th minute – on the end of Darwin Ceren's cross.
Fellow substitute Mauro Manotas completed the fightback with four minutes remaining to extend Houston's unbeaten streak to five matches.
Sporting KC are only two points clear of Seattle Sounders, who are due to play on Sunday, while Houston are third and four points adrift.
Eastern Conference high-flyers Toronto suffered a surprise 3-2 defeat against Canadian rivals the Whitecaps.
Toronto, who had their bid to set an MLS record for consecutive regular-season wins, slumped to back-to-back losses.
Jake Nerwinski's 76th-minute goal saw the Whitecaps trump Toronto at BC Place, where Vancouver snapped a three-game losing streak.
Toronto are second and two points behind Eastern Conference leaders Columbus Crew after 10 games, while Vancouver are 10th in the west.
Elsewhere, Atlanta United salvaged a last-gasp 1-1 draw at Orlando City and San Jose Earthquakes were held to the same scoreline by Colorado Rapids.