TORONTO -- The Montreal Impact stunned one of the hottest teams in MLS on Saturday by blanking Toronto FC 1-0 in the latest edition of the 401 Derby.

Ignacio Piatti's goal in the 73rd minute stood to be the winner. The Impact midfielder picked up a Dominic Oduro feed and beat a sprawling Alex Bono for his 14th goal of the season.

Toronto had an excellent chance to tie the game in the 87th minute, but Tosaint Ricketts put his header off the side of the goal.

The win is Montreal's (9-7-10) first since Aug. 6 -- a stretch of three games. It was also the Impact's first MLS victory at BMO Field, snapping an 0-3-3 stretch. With the three points, Montreal temporarily moves into a tie for fourth in the Eastern Conference.

The loss snaps Toronto's (12-8-7) stretch of five straight wins on home turf and the Reds' overall unbeaten streak at seven games. TFC remains in top seed in the East, but could be passed by New York City FC on Sunday.

Sebastian Giovinco was awarded a free kick in the 64th minute after being taken down just outside the area by Hernan Bernardello, however, Evan Bush was able to make the save. The Atomic Ant left the game soon after favouring his right leg following a challenge from Kyle Bekker and was replaced by Tsubasa Endoh.

Impact forward Didier Drogba's night ended in the 55th minute due to injury and was replaced by forward Matteo Mancosu.

Will Johnson had the first good chance of the second half, putting his header off of Drew Moor's feed into the side of the net in the 52nd minute.

The two sides played to a scoreless first half with Drogba getting the lone shot on target.

Things got heated between the two clubs in the 42nd minute after Impact midfielder Calum Mallice ran over TFC defender Steven Beitashour at midfield. Following an altercation between both clubs, Mallice was issued a straight red card while Toronto midfielder Marko Delgado was issued a yellow card.

Giovinco had an excellent chance to open the scoring in the 11th minute, but put his strike from just outside the area wide left. Two minutes later Drogba nearly put the visitor's up 1-0, but Bono was there to snag his header.

The Canadian rivals meet for a third and final time on Oct. 16 in Montreal.