The Hamilton Tiger-Cats fumbled the ball on what would have been the winning field goal Saturday at McMahon Stadium, giving the hosts a 34-32 win in wintry weather.
The Stamps secured second place in the CFL's West Division with the victory, which means they host the division semifinal Nov. 11.
"It was a game of mistakes no question about it," Stampeder head coach John Hufnagel said. "The conditions had a lot to do with it. We got a break at the end.
"I'm not going to take the shine off the victory and what it meant to this organization."
The Saskatchewan Roughriders' 34-28 loss to the Montreal Alouettes earlier Saturday opened the door for Calgary (10-6) to claim second in the division behind the B.C. Lions (12-4).
B.C. had clinched the division's top spot via a win over Edmonton the previous night. The Lions will host the division final Nov. 18.
The Ticats (5-11) weren't mathematically eliminated from the East Division's post-season with the loss, but their playoff odds remain long with two games remaining in the regular season.
Snow squalls before and during the game made for a slick McMahon surface, which contributed to the 10 turnovers in the game.
Andy Fantuz fielded the snap on the attempted field goal to win the game for Hamilton, but when he set the ball down, it slipped and Luca Congi didn't get the 30-yard attempt away as time ran out.
"It was a good snap," Fantuz said. "I put the ball down on the tee and it just went off. It's just one of those things that happens in this type of weather. It seems like it sums up our season, but we're not dead yet."
Jon Cornish scored a pair of touchdowns for Calgary. He's chasing Normie Kwong for the most running yards by a Canadian in a single season, but the slippery field wasn't conducive to the running game.
With 27 yards Saturday, the New Westminster, B.C., is 136 away from Kwong's record set in 1956. Cornish led the Stamps with 108 receiving yards, however, including a touchdown catch.
Keon Raymond ran an interception back 100 yards for a major and twice sacked Hamilton quarterback Henry Burris, who is Raymond's off-season neighbour in Calgary. Maurice Price scored his first career touchdown and backup quarterback Bo Levi Mitchell finished a drive for Calgary.
Bakari Grant and Chris Williams each had touchdown catches and Chevon Walker had a rushing major for the Tiger-Cats. Congi was good on two of three other field goal attempts. Fantuz had a two-point convert catch in the fourth quarter.
Saturday's game marked the return of Burris to McMahon for the first time since he was traded to the Ticats in the off-season.
The man who led Calgary to a Grey Cup in 2008 completed 24 of 33 passing attempts for two touchdowns. He was intercepted twice and sacked six times.
"Just the mistakes we made throughout the game came back to haunt us in the end," Burris lamented. "It's hard when it comes down to one play to decide it or whatever. That truly wasn't the deciding play, but it was disappointing for everything to finish like that."
Hamilton hurt their cause with 98 yards in penalties to Calgary's 40.
Stampeder quarterback Kevin Glenn was 22-for-34 in passing with a pair of touchdown passes. He was intercepted four times, including picks on back-to-back possessions in the fourth quarter.
"I'm very disappointed in myself," Glenn said. "I don't think I've ever had a game like that. We still got the win. Be happy about that I guess, to play that bad and still get the win."
Announced attendance was 26,542. The haze from Calgary's post-touchdown fireworks mixed with snow to reduce visibility of the field.
The snowblowers and shovels were out at halftime in an attempt give the end zone and sidelines definition and clear the yardage markers.
Conditions cleared briefly in the fourth quarter, but the snow was falling again with three minutes to go.
Walker's one-yard dive for a major with a minute remaining pulled Hamilton within two points. Burris's pass attempt at a two-point convert to Dave Stala sailed just over the slotback's fingers.
But Onrea Jones recovered Congi's on-side kick and with 54 seconds left, the Ticats were in position for that winning field goal.
Calgary recovered from a miserable first quarter — they turned the ball over three times — to lead 14-13 at the halftime.
Notes: Hamilton's Ricardo Cloclough twice intercepted Glenn . . . Calgary's Charleston Hughes had two sacks and leads the Stamps with 10. Demonte Bolden and Brian Bulcke each recorded a sack. . . Nik Lewis extended his streak of consecutive games with a reception to 156.