Liam Murphy scored the overtime winner on Saturday as the Titan used two short-handed goals to rally past the Western Hockey League's Swift Current Broncos 4-3.
The Quebec Major Junior Hockey League champion joins host Regina as the two undefeated teams at the Canadian major junior championship.
"We couldn't bury on the power play today, so those two (short-handed) goals were huge as we had to equalize the game too,'' Acadie-Bathurst captain Jeffrey Truchon-Viel said.
The Titan killed off 91 per cent of their penalties in the league playoffs and scored five short-handed goals in the process. They were scoreless on four power plays Saturday while Swift Current was 1 for 5 with the man advantage.
Adam Holwell tied the game at 3-3 in the third while shorthanded after Swift Current goaltender Stuart Skinner left a big rebound in front of the net.
Samuel Asselin, with his second goal of the game, also scored a short-handed goal at 18:07 of the second period by taking a loose puck and going in alone, beating Skinner five-hole.
Acadie-Bathurst coach Mario Pouliot said that his team benefits from a lot of speed on the penalty kill.
"No matter what, if we have an odd-man situation, for sure we're going to attack,'' he said. "If you look at our third goal, the goal of Holly (Holwell), he was one of our D kind of following the rush.''
Broncos coach Manny Viveiros said that giving up two goals on the power play is uncharacteristic of his team. He added that their power play has been a strength all season.
"When you give up short-handed goals, it is deflating at times and I thought we came back again and responded well again,'' Viveiros said.
"That's something that very easily is correctable and we'll correct that going forward.''
Swift Current lost star forward Tyler Steenbergen early in the second period after getting checked awkwardly into the boards by Truchon-Viel.
The Canadian gold medallist at the world junior championship didn't return to the ice and Viveiros said he's day-to-day.
Truchon-Viel said that he was just finishing his check and that it's a part of hockey.
Murphy's winner came when he jammed home a loose puck in front of the net at 2:58 of extra time. Evan Fitzpatrick stopped 24-of-27 shots for the win in net.
Giorgio Estephan scored twice for the Broncos while Steenbergen had the other goal. Skinner made 35 saves.
The crowd was filled with blue and green Broncos jerseys with plenty of fans bringing their blowhorns and cowbells on the two-hour drive from Swift Current.
Estephan's second came just over a minute after Asselin's second goal of the game when he collected his own rebound and backhanded it past Fitzpatrick.
The Broncos took their first lead of the game just before the end of the first when Estephan one-timed a shot past Fitzpatrick after a cross-ice pass from Colby Sissons.
Asselin opened the scoring on a nice re-direction from a Olivier Galipeau slap-pass that beat Skinner.
Steenbergen equalized the game at 1-1 at 12:18 of the first on the power play when he jammed home a loose puck off a scramble in front of the net.
The Titan have a quick turnaround and face the host Regina Pats (1-0) on Sunday. Swift Current faces the Ontario Hockey League's Hamilton Bulldogs (0-1) on Monday night.
Note: Attendance at Brandt Centre was 6,237.