FC Dallas claimed top spot in the MLS Western Conference after overcoming Los Angeles FC, while Philadelphia Union had two players sent off in their loss to Atlanta United.

In-form Dallas moved ahead of Sporting Kansas City by a point in the west thanks to Saturday's 2-1 victory against 10-man LAFC – the club extending their unbeaten streak to six games.

Ex-Tottenham defender Reto Ziegler opened the scoring with his first MLS goal in the 25th minute – the Dallas left-back heading a stray ball past Tyler Miller at Toyota Stadium.

Former Swansea City winger Roland Lamah doubled the lead six minutes into the second half courtesy of a well-taken finish inside the penalty area.

Adama Diomande came off the bench and pulled a goal back 10 minutes later but LAFC – who had substitute Jordan Harvey sent off for a second yellow card in the 89th minute – slumped to their fourth successive match without victory.

Josef Martinez scored a hat-trick as Eastern Conference leaders Atlanta stayed top via a 3-1 win at home against nine-man Philadelphia.

A first-half penalty triggered a wild sequence for the Union, who had Alejandro Bedoya and Haris Medunjanin both sent off for arguing the referee's decision in the 19th minute.

Martinez converted the spot-kick before completing his fifth hat-trick in the second half as Atlanta maintained their two-point lead atop the east following New York City's 3-0 victory over struggling Orlando City.

Zlatan Ibrahimovic – who scored twice in a 3-2 loss to Dallas last time out – started on the bench in LA Galaxy's 1-1 draw at Portland Timbers, while Sebastian Giovinco scored a stunning free-kick as Toronto surrendered a three-goal lead in their 3-3 draw against Columbus Crew.

Montreal Impact edged Houston Dynamo 1-0, Real Salt Lake accounted for Seattle Sounders 2-0, Chicago Fire defeated San Jose Earthquakes 2-1 and New England Revolution trumped New York Red Bulls by the same scoreline.