Marco Di Vaio got the goal they needed in the 14th minute and the Impact held on for a 1-0 victory over the winless New York Red Bulls on Saturday.
It left the second-year MLS club at 4-0-0 to start the season. As an expansion club in 2012, it took until their 14th match on June 16 to get a fourth victory.
"We're in a good way now in terms of results," captain Davy Arnaud said. "The performance was also better than last week against Toronto (a 2-1 win in their home opener)."
The Red Bulls (0-2-2), who were held without a goal for a second week in a row, finished the match shorthanded as defender Brandon Barklage was sent off for taking Patrice Bernier down at the edge of the penalty area in the 74th minute.
The same scenario occurred when New York visited Montreal last season and the Red Bulls managed to score twice while down a man to pull out a 2-1 win.
This time, Montreal closed ranks, with veteran centre back Matteo Ferrari masterful at anchoring the defence, to maintain the clean sheet.
"We didn't fear it would repeat itself, but we were aware of it," said Arnaud. "We got together at midfield and said 'this is the exact situation.'
"They had some fresh legs coming in and were pushing guys forward, but we stayed solid and ended the game well."
The Red Bulls had 58 per cent of the possession and equalled Montreal with seven shots on target, but the Impact had more and better chances throughout the game.
Now the Red Bulls will try to get a win next Saturday at home against Philadelphia.
"This really stung," said goalie Luis Robles. "I felt like we did a lot of things good, but sometimes that's not good enough.
"We all know it's a long season, but we don't want to be looking 10 or 15 games in and thinking 'OK, there's more of the season left.' It doesn't work that way.
"We wanted to do bring the game to Montreal. We were doing that, but also give credit them credit. Montreal is very organized and compact. There's a reason they're 4-0."
Montreal will try to make it five in a row next Saturday at Kansas City.
Impact coach Marco Schalibaum had some surprises as he juggled his back line in the absence of injured centre back Alessandro Nesta to put more accent on the attack.
He mostly used a three-man line with Ferrari in the middle. Defender Hassoun Camara played mostly on the right side of midfield and had some promising runs, but he would scurry back to the defence when needed.
The biggest surprise was seeing 20-year-old Karl Ouimette, who last season became the first academy player signed to the main team, get his first MLS start. The Terrebonne, Que., native did well.
"I only told a restricted amount of people — parents and friends — I was playing," Ouimette said. "I wanted to concentrate and not do a huge media announcement.
"That would just put more pressure on. I wanted just to be in my bubble. The coach showed a lot of confidence in me and I wanted to give him the performance he wanted."
He even had a scoring chance, but didn't get enough on a header off a corner kick in the 56th minute.
Camara and Ferrari helped talk Ouimette through his first match and gave him some early touches on the ball when there was no pressure to get a feel for the game.
"We knew it was his first game against a very good team,"said Camara. "I think he did well. We're very proud of him."
The score could have been one-sided with a little more finish in their game.
A crowd of 26,259 saw Di Vaio whiff on a perfect set-up from Andres Romero, have a shot from the left side blocked by Robles and tip another ball just wide in the second half alone.
The Impact scored first for a fourth straight game in the 14th as goalkeeper Troy Perkins sent a long ball up the middle that was headed down to Bernier.
The canny playmaker slipped a pass through the New York defence to Di Vaio, who went left side on Robles for his second of the season.
The Red Bulls new signing from Paris St-Germain, Peguy Luyindula, played his first game at forward and had his side's best chance of the first half. A Heath Pearce attempt off Juninho's free kick was deflected by Perkins to the top of the box, where Luyindula chipped it over the bar in the 38th minute.
And he was in front again in the second but only got a touch on a feed from the right side and was stopped by Perkins.
Camara made a pretty play to Di Vaio 36 minutes in, but Robles came out to shut off the attempt.
More surprising than Ouimette starting was that fullback Zarek Valentin, one of their top expansion picks last season, was a healthy scratch.
"It's the coaches' decision," said Valentin. "We got the win, so you can't complain too much. Karl played well."
The Impact played their first two home games in the Big O dome and will move outdoors to Saputo Stadium for an April 16 match with Columbus.
Notes: Thierry Henry (knee) wasn't available for New York. ... Montreal's Sanna Nyassi was away for the World Cup qualifier for Gambia, while Red Bull's Tim Cahill was away with Australia.