CALGARY — The Calgary Stampeders silenced speculation about game rust by thumping the B.C. Lions 42-15 in Sunday's West Division final.

The Stampeders are the heavy favourite in next Sunday's Grey Cup in Toronto, where they'll face the Ottawa Redblacks in the CFL's championship game.

The Stampeders (15-2-1) and Lions (12-6) posted the CFL's best regular-season records, but Calgary controlled the division final from right from kickoff.

Calgary hadn't played a game in three weeks because of back-to-back byes. Quarterback Bo Levi Mitchell hadn't thrown a game ball in almost a month.

But the Stampeders scored on their opening drive and raced to a 32-0 lead by halftime in front of an announced 32,115 at McMahon Stadium.

"I knew from moment I woke up that we were going to walk out here and look like this," said Mitchell, who threw for 365 yards and three touchdowns.

"I know we made it look easy. It wasn't. It was two tough weeks of game planning and preparation and guys coming in and executing at a very high level."

Ottawa, who went 8-9 in the regular season, downed the visiting Edmonton Eskimos 35-23 in a snowy, slippery East final Sunday.

Stampeders head coach Dave Dickenson was thankful the West final had dry, mostly sunny conditions for his players to execute to their potential.

"I watched the East final and that weather was just crazy," Dickenson said. "We had a beautiful day, a beautiful night. When that happens, your skill can be showcased."

Calgary will play in its fourth Grey Cup game — winning in 2008 and 2014 — since John Hufnagel became general manager in 2008.

But this is the Stampeders' first Grey Cup appearance with Dickenson as head coach. Hufnagel handed the coaching reins to him this season.

Mitchell, a finalist for the CFL's Most Outstanding Player award, threw touchdown passes to Lemar Durant, Marquay McDaniel and DaVaris Daniels, plus a two-point convert throw to Kamar Jorden.

Rene Paredes kicked field goals from 26 and 34 yards.

Durant led the host team with a pair of touchdowns — one on the ground and one in the air.

"We came out blazing. No rust at all," Durant said. "We played the game so sound.

"We just use this as momentum and if we play (in the Grey Cup) the way we played today, then I feel like there's no stopping us."

The Stampeders defence did their part holding the top-rushing team in the league to 84 yards on the ground, while defensive back Jamar Wall scored off an interception.

The Lions threatened late in the first quarter, but a Ja'Gared Davis tackle on Rainey for a six-yard loss forced the visitors to punt.

"I think three times we can't convert on second-and-two," Lions head coach Wally Buono lamented. "All of a sudden, you're punting and punting and punting and your defence is exposed and exposed and exposed, and the last thing you want to do is be exposed to Bo Levi. He's gonna hurt you, which he did."

B.C.'s Chris Rainey and Emmanuel Arceneaux caught touchdown passes from Lions starter Jonathon Jennings and backup Travis Lulay respectively.

Lulay replaced Jennings to start the second half, but Jennings was back in before the end of the third quarter.

Jennings completed 15-of-22 pass attempts for 161 yards and one touchdown. Lulay was 6-for-9 for 86 yards.

"They hit us in the mouth early and we never counter-punched," Lulay said.

The door opened slightly for the Lions in the third quarter when Calgary turned the ball over on offence and B.C.'s Anthony Gaitor intercepted a Mitchell pass intended for Jorden in the end zone.

But Stampeders linebacker Glenn Love snuffed out B.C.'s momentum by picking off Lulay throwing to Bryan Burnham in the end zone in the final minute of the quarter.

"What I liked is we held our composure," Dickenson said. "We were very excited, but we weren't over-excited. You could sense there was a calm there. The guys trusted what we were doing.

"We've got a purpose. We're playing for a lot of things this year. More than ourselves. By saying that, it's going to take one more huge challenge. I believe in our guys and I think we'll be ready."