In the end, that proved just enough.
Montreal scored three first-half goals and held on for a 4-2 win against the Vancouver Whitecaps at Stade Saputo on Tuesday, one week after losing 2-1 at Vancouver.
"There were some nervous moments at the end, for sure," Impact coach Mauro Biello said. "I think you've got to learn from them but we've also got to live those moments. You've got to live those moments and come out of there by holding on, and that's how you grow as a team. And for me, I think that's a positive."
The Impact, who won 5-4 on aggregate to advance to the final, had a week off between the two games; the Whitecaps lost 1-0 to D.C. United in an MLS regular season game at B.C. Place on Saturday.
Montreal will meet the winner of Wednesday's semi-final between Toronto FC and the Ottawa Fury of the NASL.
Meanwhile, the Impact have four days before returning to league action at home against the New York Red Bulls on Saturday, a long enough break that Biello felt comfortable putting out his best starting XI against the Whitecaps.
"We knew we were going to leave some guys behind when we flew out to Vancouver and do enough to make it close enough so that we could win it back home," Biello said. "And we felt that also the four days in between the New York game is enough to recover.”
Biello also knew Vancouver counterpart Carl Robinson didn’t have that luxury.
“For sure [Robinson] had to mix the lineup to travel having played Saturday,” Biello said. “But in the end, that's the schedule, and it worked out for us. And now we advance."
Impact midfielder Ignacio Piatti gave Montreal a 2-0 lead when he scored on consecutive penalty kicks, the first 20 minutes in and again in the 28th minute.
Blerim Dzemaili’s first goal in North American competition made it 3-0 in the 38th minute to give Montreal what appeared a comfortable advantage.
The Whitecaps had other ideas.
"I said to them at half-time, 'It's easy to go under, but let's not go under,'” Robinson said of his halftime talk. "'Let's show how good we are, or we can be, and let's try and win that second half,' and we did. And we kept fighting, which is really positive for these young players because a lot of them haven't played too many games."
Vancouver rallied to within one goal on aggregate twice, the second time on Kyle Greig's header in the 77th minute. Another goal would've given the Whitecaps the semifinal on the away goals rule.
The fully-rested Impact just had a little more gas.
"They came back, they battled and scored two goals, even all the way to the end it was only one goal, but it was good to have a solid, complete performance," Montreal midfielder Patrice Bernier said. "We haven't had many of those so it was nice to have a victory and a performance like that today."