It was one of the more bizarre scenes one will see in professional sports.
The Saskatchewan Roughriders were in full party mode, galloping onto the field to celebrate the franchise's second Grey Cup win in three seasons after Montreal's Damon Duval missed a 43-yard field goal attempt that would have won the game for the heavily-favoured Als.
But celebration stopped colder than a Regina winter night when the players suddenly noticed a red flag lying under the goal post, followed by the announcement that Saskatchewan had lined up with too many men on the field.
That gave Duval another shot and this time he made good from 33 yards, making the final score 28-27 and sending his teammates rushing onto the field for a celebration from the opposite sideline from which the Roughriders had had to abort theirs.
"There were 13 men on the field," said head coach Ken Miller. "There was a lack of communication. We thought we won the football game. It's just totally 100-per-cent disappointment. That's going to be a disappointment that will be with our football team for their lifetimes."
For more than three quarters, the Alouettes had danced with infamy, on their way to a stunning record of six Grey Cup losses in seven championship games this decade.
But early in the fourth quarter of the 97th Grey Cup game, with most of the 46,020 at McMahon Stadium in green-clad jubilation, the sleeping giant final woke up.
Montreal quarterback Anthony Calvillo, whose first half had brought back a lot of bad Grey Cup memories for Montreal fans, brought his team back, hitting receiver Brian Bratton with a 33-yard pass that put the ball on the Saskatchewan three-yard line, from where Avon Cobourne carried it in to make the score 27-19 after a successful two-point conversion.
On Saskatchewan's next series, Saskatchewan quarterback Darian Durant and receiver Andy Fantuz, so often in synch this season, misread each other and the ball landed into the arms of Montreal defence back Jerald Brown.
That gave the Als the ball just over midfield and a few moments later, Calvillo hit Ben Cahoon with an 11-yard pass with just 2:09 to play to make it 27-25.
When the Als failed to make a two-point conversion, the game was in the Roughriders hands to try and run out the clock.
But when Saskatchewan went two-and-out, Montreal got the ball back at their own 34-yard line with 40 seconds to play. Calvillo then got his team into field goal range from where the dramatic final events of the game unfolded.
The Roughriders, who had held Montreal to just a field goal in taking a 17-3 lead to the locker room, appeared on their way to winning their second Grey Cup game in three seasons when quarterback Darian Durant ran 16 yards to the end zone to put his team up by 27-11 with 10:32 to play.
Montreal had almost no experience rallying for wins, having spent most games this season with a comfortable lead in the fourth quarter en route to 16 wins and just three losses headed into Sunday.
And yet that's how the CFL's most dominant team from this season spent most of Sunday's game, their only lead of the entire game occurring when the clock said zero.
A shocking first-half began with Montreal going two-and-out on their first two possessions, then fumbling the ball away when Calvillo was hit by Saskatchewan's Marcus Adams and Keith Shologan recovered.
On play later, Durant hit Andy Fantuz for an eight-yard touchdown that gave the Riders a 10-0 lead, swung the momentum clearly in Saskatchewan's direction and sent a mostly green crowd into a frenzy.
At that point, with 1:19 remaining in the first quarter, the league's highest scoring team during the regular season, which blew-out points on the B.C. Lions one week earlier, was being out-done 136-9 in total offence.
The Als replied with a field goal and then appeared to be heading for more when fullback Kerry Carter caught a pass and then fumbled where it was recovered by the Riders Chris McKenzie at the Saskatchewan 17. Operating with just eight seconds to play, Durant through a pass to Fantuz which the officials originally ruled incomplete as time expired.
But Saskatchewan head coach Ken Miller dropped his challenge flag and the call was reversed, placing the ball on the two-yard line with two seconds to play.
Luca Congi's nine-year field goal as time expired gave the Als a 17-0 lead and Montreal head coach Marc Trestman apparently flabbergasted.
"We feel very fortunate to be down by 14," said Trestman before going to the locker room at halftime.
Fortunate, and apparently compelled to make amends.