Coreau made 29 saves as the Griffins came back from 1-0, 2-1 and 3-2 deficits for a 4-3 victory over the Crunch in Game 6.
Coreau was tested throughout the game but never more than in the last 7:19 after Martin Frk scored the go-ahead goal in the third.
"This is a huge step in his career," Griffins coach Todd Nelson said. "A lot of people thought that he couldn't win a championship. He said to me (Tuesday) morning, 'I'm going to prove to everyone that I'm a champion.' He did that tonight."
When Jimmy Howard suffered a serious knee injury Dec. 20, the Red Wings called on Coreau.
In 14 games with Detroit, Coreau was 5-4-3 with a 3.46 goals-against average and .887 save percentage. Coreau did have two shutouts, against the Los Angeles Kings and Montreal Canadiens.
"I think that two and a half, three months I was up was probably the most beneficial thing," Coreau said. "I learned how to be a real pro. Being around some of those guys who have won the Stanley Cup, you just see how they carry themselves. I think that's how I tried to emulate myself down here."
Coreau played in three playoff games for the Griffins last season but started all 19 games this postseason.
"Everyone knows he's good," Frk said. "He prove it over the whole year. He did amazing. If we wouldn't have him, maybe we wouldn't get all the way here. He stood on his head, he made so many saves. He's ready for probably the next step."
Coreau was overjoyed to hoist the Calder Cup with his teammates in front of the home fans.
"I said it from the beginning of this year, that was my goal, that was our goal," Coreau said. "We did just exactly what we wanted to do. It hasn't really soaked in yet, I don't think. Just watching everyone hold it here, I love all these guys."
THE TWO-TIME CHAMPS: There were three Griffins who knew just what it felt like to win a Calder Cup because they had done it before.
Captain Nathan Paetsch, defenseman Brian Lashoff and forward Mitch Callahan were all on the 2013 team that won with coach Jeff Blashill.
"It's amazing," Paetsch said. "After the first time, you just want it that much more. You don't realize it. It was my first championship, makes you so hungry and this group was so special all year. The camaraderie was incredible. All the way from the staff to the coaches to the players, it was such a family. To win it meant so much."
In 2013, the Griffins beat the Crunch for the Cup but won it on the road. "Doing it at home's pretty nice," Lashoff said. "It's amazing when you start in October, you do all this work, you bring it all the way to June, I think it's just amazing what these guys have done. It's been a long road but it's been fun."
Callahan said it was just as good to win the second time, but doing it at home was the icing on the cake.
"It's unbelievable," Callahan said. "I'm getting chills just looking around. These fans are the best fans in the American Hockey League. I'm proud to be able to lift the trophy in front of them."
Winning it again with the other two is something Paetsch appreciates.
"We're brothers," Paetsch said. "To spend that amount of time together in the organization, it's an honor to be here and to be with those two guys is special, to be able to do it again. Who knows where the future will bring us. It's special to be able to do it with them again."
For Paetsch, this championship had extra meaning because he was able to share it more with his young children.
Paetsch's son, Kellen, is six and his daughter, Mira, is four. Mira was just born the last time the Griffins won.
"It means everything in the world to me," Paetsch said. "They're going to remember this for the rest of their lives. Last time it was chaotic, they were young, my daughter still wasn't sleeping yet so it was hard to really enjoy the experience. Now they know what's going on. My son's six, he knows exactly what's going on. It's everything."
ROOKIES ROCK: On the other end of the spectrum, the Griffins also relied on rookies during their championship run. Evgeny Svechnikov, Kyle Criscuolo, Joe Hicketts, Dan Renouf and Dominic Turgeon all played in the postseason.
Filip Hronek played in two playoff games, while Axel Holmstrom, Dylan Sadowy and Mike Borkowski practiced with the team but did not play.
"They stepped up," Nelson said. "Kyle Criscuolo. Dominic Turgeon, we put him on a line with Matt Ford and (Colin) Campbell, they were shutting down (Cory) Conacher's line tonight, that was their role. They wanted the role, they did well. Joe Hicketts, I can go through all the guys. Guys that didn't play in the playoffs that helped us get wins. Sadowy, Borkowski, Hronek, Holmstrom, all these guys contributed. Just a great group."
Svechnikov had five goals and seven assists, Criscuolo had five goals and four assists, Hicketts had one goal and seven assists, Renouf had two goals and two assists and Turgeon had one goal and one assist.
"It's the best feeling," Svechnikov said. "I think it means a lot. You go through all your life and you battle every single day, every hour in practice and here we are, winning the Cup with this group of guys. It's huge. All life you're thinking about, it's going to be forever."
"We're one-for-one," Criscuolo said, smiling.
"Definitely starting our career with a Calder Cup championship is unbelievable," Renouf said. "It's such a great group of veterans here that welcomed us and couldn't be better."
A veteran had some wise words for the kids.
"I'm telling them to cherish this moment because this doesn't happen very often," Callahan said. "We won it my first year, now this one I'm trying to soak everything in."
Paetsch recognized that without the contributions of the young players, the Griffins would not be celebrating the way they were Tuesday night.
"That's how you win a Calder Cup," Paetsch said. "You got to have guys step in and play huge roles. Svechnikov, Criscuolo, Hicketts, those guys stepped in and they were elite on our team. That's the difference. You can't just win it with veterans, that's not how the league works."