LA Galaxy suffered their first loss of the MLS season, while Minnesota United maintained their perfect start on Sunday (AEDT).
Without Zlatan Ibrahimovic, who was sidelined due to an Achilles injury, Galaxy went down to Dallas 2-0 in Texas.
Reto Ziegler's 53rd-minute penalty gave Dallas the lead and their win was sealed by Bryan Acosta, who struck from 20 yards.
Strugglers last season, Minnesota made it two from two courtesy of a 3-0 victory at San Jose Earthquakes.
A Darwin Quintero penalty, Miguel Ibarra strike and Harold Cummings own goal lifted Adrian Heath's men to their win.
Seattle Sounders also claimed a second straight win by beating Colorado Rapids 2-0.
Kelvin Leerdam and Raul Ruidiaz scored in the opening eight minutes in the Sounders' victory.
Elsewhere, a 10-man Chicago Fire held Orlando City to a 1-1 draw thanks to CJ Sapong's 95th-minute equaliser.
Gyasi Zardes' brace led Columbus Crew past the New England Revolution 2-0, Houston Dynamo edged Montreal Impact 2-1 and Real Salt Lake beat Vancouver Whitecaps 1-0.