The Fire played well enough to come out of Los Angeles with at least a point but the finishing touch in the final third eluded them most of the night and defensive miscues erased an early second-half gift from the home team.
Newcomers David Ousted and Przemyslaw Frankowski were impressive in defeat while CJ Sapong, playing place of Nemanja Nikolic took advantage of a 49th minute turnover to give the Fire a lead.
In the 67th minute Jorge Corrales unnecessarily surrendered a corner kick which led to 16-year old LA rookie Efrain Alvarez beating Aleksandar Katai on the dribble to find Daniel Steres for a clean header in front of the net.
In the 80th minute, Corrales lost his mark on a throw-in and then helped Zlatan Ibrahimovic's rebound header into the net to give LA the lead for good.
Ousted; Campos (Hasler 73'), Marcelo, Kappelhof, Corrales; McCarty, Schweinsteiger; Frankowski, Mihailovic (Bronico 77'), Katai (Martinez 68'); Sapong
Subs not used: Sanchez, Lillard, Herbers, Nikolic
Campos - 5.5
Corrales - 3.5
Frankowski - 7
Mihailovic - 6
Bronico - 5.5
Katai - 5.5
Martinez - 5.5
Sapong - 6