LAFC came into BBVA Stadium two days after playing in the quarterfinals of the U.S. Open Cup.
Coach Bob Bradley started only three regular starters -- Tyler Miller, Steven Beitashour and Mark-Anthony Kaye.
And it was playing the Dynamo, which was unbeaten at home in 10 MLS games.
Still, LAFC prevailed, rallying from a 1-0 deficit after three minutes to win going away and open up a 10-point lead over Philadelphia in the Supporters' Shield race and 12-point lead over the LA Galaxy in the Western Conference.
A goal-line clearance by defender Mohamed El-Munir in the 26th minute kept the game close, and then midfielder Lee Nguyen and forward Adama Diomande took over.
Nguyen set up Diomande for goals on either side of halftime, and Josh Perez, in just his second MLS start, fed Diego Rossi, who came off the bench, for the insurance goal.
“We had a nervous start," said LAFC head coach Bob Bradley. "A lot of guys got a chance to play tonight that don’t normally play, and you could see the nerves. We give up the early goal, need a save or two from Tyler [Miller] and an incredible play from Mohamed El-Munir just to keep it at one, but little by little in the first half we started to play a little of the kind of football that we’ve been playing all year; and then the second half was a real strong push. Once we got the lead, I thought we handled it well."
Bradley praises both the players who stepped into the lineup and Kaye and Beitashour, the two players who started in the 1-0 loss to the Timbers on Wednesday.
"I thought Dejan Jakovic and Tristan Blackmon had really good games in the center of the defense," he said. "It was a big game for Dio to score some goals, so again it just was a team effort. And look, for Mark-Anthony Kaye and Steve Beitashour to play 90 minutes here tonight after playing in the Open Cup match less than 48 hours before, that’s incredible. All credit to the guys and the mentality that they brought to this game.”