Defender Diego Polenta headed in the winning goal in the 88th minute to lift the Los Angeles Galaxy to a 2-1 victory over the Houston Dynamo on Friday night at Carson, Calif.
Forward Zlatan Ibrahimovic also scored as the Galaxy (6-1-0, 18 points) continued their strong start.
Forward Alberth Elis scored for the Dynamo (4-1-1, 13 points), who fell from the ranks of the unbeaten. The Seattle Sounders (5-0-1, 16 points) are the lone remaining undefeated MLS squad.
Polenta's goal came off a strong corner kick by midfielder Jonathan dos Santos, who delivered the ball into the box. Polenta went up and snapped the ball with his head and it sailed past Houston goalkeeper Joe Willis into the right corner of the goal.
It was Polenta's first goal in six games during his initial MLS season.
Ibrahimovic has seven goals in five games this year.
Los Angeles had a corner kick in the 29th minute, and Houston defender A.J. DeLaGarza was caught with his hands draped around Ibrahimovic's midsection as the ball traveled near the goal.
That resulted in the penalty-kick call, and Ibrahimovic lined up for the shot. Willis guessed correctly while moving to his left and got his left hand on the ball but the force of Ibrahimovic's kick was too much as the ball went into the net to give the Galaxy a 1-0 lead in the 31st minute.
Houston knotted the score in the 53rd minute on Elis' penalty kick.
Galaxy defender Jorgen Skjelvik was called for dragging down Elis on the edge of the box. The play was reviewed, and it was determined that the call was correct.
Elis set up for the kick and sent a hard right-footed ground shot toward the left post. Galaxy goalkeeper David Bingham dived for the ball, and it skidded past his outstretched right hand and into the net.
Los Angeles had a chance to take the lead in the 73rd minute when Ibrahimovic threaded a pass to forward Emmanuel Boateng, but Willis moved forward and thwarted Boateng's close-range shot.
Ibrahimovic came up empty on headers in the 74th (saved by Willis) and 78th minutes (wide left).
Elis had a golden opportunity for a second goal in the 81st minute, but his right-footed blast was just wide of the right post.
Houston forward Mauro Manotas had a close-range shot in the 84th minute that was stopped by Bingham.