A third successive defeat does not bode well for the Quebecois side as the MLS season approaches its conclusion.
Defending a corner kick, Evan Bush and the Montreal back line were able to drive the first few attempts on goal away, but LA kept coming, and Opare, making just his fourth career start, found the net with a fluid turn-and-shot effort.
Montreal now must ask itself questions after falling to a fifth defeat in six games and its season on the line. Marco Schallibaum's charges were considerered among the Supporters' Shield favorites in the beginning of the season.
Now Montreal (13-12-7) is in favor of missing out on the playoffs entirely, tied on points with the fifth-place chicago fire and sixth-place Philadelphia Union, who will visit Stade Saputo on Saturday licking their chops at the thought of overtaking the Impact.
Los Angeles (15-11-6) is now just two points shy of reclaimng the MLS Supporters' Shield, but it's a crowded top. LA has 51 points, tied with Seattle, and trails New York and Portland on 53 and Kansas City and Salt Lake on 52.