Victor Wanyama and Montreal Impact failed to build on their recent good form after they went down to Philadelphia Union in a 2-1 defeat on Sunday.
Montreal Impact had ended what had become a poor run by drawing against Chicago Fire before handing Columbus Crew SC a first defeat of the year but the latest results mean the momentum has been slowed.
The win ensured Philadelphia Union are in second place on the Eastern Conference table after a match that included the fans for the first time since the coronavirus pandemic.