Lassi Lappalainen scored in the 86th minute to prevent Montreal from being shut out.
Montreal (5-7-1, 16 points) has dropped three straight matches and four of its last five. The Impact have been outscored 10-3 during the three-game slide.
Montreal goalkeeper Clement Diop had four saves.
The Revolution outshot the Impact 20-7 and placed seven shots on target. Montreal put four shots on net.
New England broke a scoreless tie after lining up for a corner kick in the second minute of first-half stoppage time.
Lee Nguyen took the kick from the right side and launched the ball into the mix of players and it headed in the direction of Kessler. He knocked the ball down with his chest and unleashed a hard right-footed shot into the right corner of the net for his first career MLS goal.
The Revolution added on in the fourth minute of the second half as Bou dribbled in and appeared to be closely marked. But his pass was blocked and caromed right back to him. He saw an opening and delivered a right-footed shot that found the lower left corner for his fourth goal of the season to give New England the 2-0 advantage.
The Revolution tacked on the third goal in the 65th minute. Tajon Buchanan slid a pass over to his left to Fagundez, who easily completed a right-footed shot into the right corner of the net for his first goal of the season.
Turner was looking for his fifth shutout of the season but that bid ended after Emanuel Maciel found a streaking Lappalainen open in the midfield. Lappalainen dribbled in toward the goal and easily beat Turner with a shot into the right corner for his second goal of the campaign.