A resounding Montreal win was made even sweeter as Marco Di Vaio took the league lead in goals.
Despite the absence of head coach Marco Schallibaum through suspension, the Quebecois had little trouble carving open the Texan side over and over throughout the match.
Marco Di Vaio scored Montreal's first in the 35th minute. Justin Mapp, at the top of the penalty area, played a pass wide to the Italian veteran. Di Vaio cut inside, made a move on Corey Ashe, and slotted home his 14th of the year, tying him for the MLS lead.
Felipe made it 2-0 barely two minutes later. Di Vaio charged into the Houston penalty area but was dispossessed. Following him up, Mapp collected and crossed for Felipe, who settled and curled a perfectly placed shot. Tally Hall stood motionless on his line as it went it.
Jeb Brovsky turned in Montreal's third in the 58th minute. Hernan Bernardello's corner was tipped by the head of Dynamo midfielder Brad Davis, but it fell to Brovsky at the far post, who evaded Will Bruin's coverage to poke a shot home.
Montreal then put the game beyond reach and put Marco Di Vaio atop the goal-scoring leaderboard. Patrice Bernier unselfishly set up the forward as the two beat Houston's offside trap and took on the unprotected Hall. Di Vaio's easy finish gave him his league-best 15th goal of the campaign.
And another Italian, Andrea Pisanu, made it five in stoppage time, running onto a Felipe through ball that bypassed the entire Houston midfield and defense.
The win gives Montreal 41 points on the season and first place in Major League Soccer's Eastern Conference. The Impact are now just a point behind Real Salt Lake in the Supporters' Shield standings, and they've played two fewer games. Houston is still in control of the fifth and final playoff spot in the East, but leads Chicago by just two points.