Marco Di Vaio scored six minutes from time to give Eastern Conference bottom club Montreal Impact victory against playoff-chasing Chicago Fire.
The 38-year-old Italian scored the decisive goal with his only shot on target of the game, and his effort proved too good for Sean Johnson in the Fire goal.
In a game light on goalmouth activity, Montreal could have gone ahead earlier in proceedings when a Dilly Duka through ball on the hour mark found Andres Romero, but his low shot from the edge of the box was saved by Johnson.
Chicago almost snatched a point at the death when Jeff Larentowicz rifled a shot from six yards out, but Evan Bush was on hand to keep his effort out.
Montreal were able to hold on for a rare victory, but remain eight points adrift at the foot of the Eastern Conference.