Both teams emphasized the positives after Wednesday night's draw at Saputo Stadium.
The Whitecaps are happy to have home-field advantage in the deciding game at B.C. Place on May 29, though Montreal can secure a crucial tie-breaker with an away goal in the two-game, total-goals final.
"I guess both teams will be aware that they won't want to take an away goal if we go out there and lead 1-0," Impact captain Patrice Bernier said. "I'm thinking it's going to be a more open game. It's going to be a final so at the end it's going to be the last game. There's no third game that's going to be played. It's either going to go into overtime or it's going to be solved in 90 minutes."
Whitecaps goalkeeper Brad Knighton posted the clean sheet and Vancouver's Alain Rochat had two solid scoring chances in the first half, including a header off a corner kick in the 32nd minute that was stopped on the goal-line by Montreal midfielder Justin Mapp.
"We're happy with the result tonight," Rochat said.
Vancouver defender Andy O'Brien acknowledged that the Whitecaps will have to move away from the concentrated defensive approach the team took in the opening leg.
"I think maybe in the second leg we'll have to open up a little bit but we've got plenty of time to prepare for that," O'Brien said.
Impact defender Jeb Brovsky was bloodied about the face in the 88th minute when he collided with Vancouver's Jordan Harvey as both went up for a ball kicked deep into the box by Montreal defender Matteo Ferrari.
Brovsky, who returned to finish the game, went to the hospital after the game to check for a broken nose and possible facial fractures.
"That's Jeb. He's a warrior," Impact coach Marco Schallibaum said. "His nose was over here (on the side of his face). You have to respect a player like that because he gives it his all."
The Whitecaps are appearing in their third championship series since the tournament format changed in 2011 from a round robin to two playoff rounds. Vancouver lost the first two ACC finals to Toronto FC, which won four straight Voyageurs Cup titles from 2009-12.
"I thought we did a good job of shutting them down," Whitecaps coach Martin Rennie said. "We had a couple of chances ourselves and it would have been nice to have stolen one of those, but I think we've given ourselves a good chance going into the second leg."
Impact striker Marco Di Vaio lifted his arms to appeal, though to no avail, for a handball in the 74th minute when his shot from inside the box off a pass from Brovsky was blocked.
Montreal goalkeeper Evan Bush jumped to stop Erik Hurtado's shot in injury time at the end of the second half.
Di Vaio had a scoring chance 19 minutes in when he curled around to the front to fire a shot from 25 yards out. Whitecaps goalkeeper Brad Knighton made the stop but had to scramble to recover his rebound.
Montreal captain Patrice Bernier put a shot just wide of the right post moments later in the 21st minute.
Vancouver threatened in the 32nd minute when Rochat's shot was stopped by Bush.
Rochat had a second straight opportunity to go for goal on the ensuing corner kick but Mapp blocked his header just inside the right post.
Montreal coach Marco Schallibaum exchanged heated words with Whitecaps assistant coach Paul Ritchie on the sidelines after the Impact picked up its third yellow card in a span of seven minutes when Di Vaio was cautioned in the 33rd minute for his tackle on Matt Watson.
Defender Hassoun Camara was shown Montreal's first yellow card for fouling Vancouver captain Nigel Reo-Coker on a hard tackle 26 minutes in.
The Impact's Collen Warner was also cautioned in the 31st minute.
"There could have been three, four, five or six cautions the other way," Schallibaum said.
O'Brien picked up a yellow card in the 49th minute.
Afternoon rain and a forecast of evening showers that did not materialize kept the crowd to 12,016.