A day of hope turned into a day of despair for the Saskatchewan Roughriders on Saturday.

The day began with the Riders having an outside chance of finishing first in the CFL's West Division, but a 28-27 victory by the Winnipeg Blue Bombers over the Montreal Alouettes ended that hope.

Then the Riders took to the field against the Calgary Stampeders in their regular-season finale and put in a lacklustre effort that resulted in a 27-12 defeat.

The Winnipeg victory, coming on a 51-yard field goal by Sergio Castillo on the final play of the game, snatched the possibility of finishing first from the Riders. The ensuing mental letdown played a major role in the loss to the last-place Stampeders.

"We obviously didn't play how we wanted to play today. I don't want to bank it on a letdown being the reason, but you never really know. We were prepared to play hard regardless but I think that kind of gave guys a little bit of letdown. But I think it probably wasn't an excuse at all, to be honest," said Saskatchewan linebacker C.J. Reavis.

"We shouldn't be waiting for somebody else to do the work for us again. We should have hit our business, so we really didn't deserve the spot, to be honest. We should have won earlier in the season for the spot. We didn't get it reserved."

Riders head coach Corey Mace believed his players could handle the disappoint of the Winnipeg victory, but he acknowledged the letdown.

"It sure felt like it and I wish it didn't. At halftime, we spoke about it a little bit, and even before the game, the goal was always the goal, we've got to go 1-0. There were some guys who had an opportunity to play who maybe hadn't seen an extensive amount of playing time," said Mace.

"Everybody was excited about that, and those guys are part of this team and help us win. I just, I just didn't feel like we had the juice tonight and it showed."

Saskatchewan started the season with a 4-0 mark before stumbling through a nine-game winless streak with an 0-8-1 record. Mace agreed that if the Riders could've won a game or two during that stretch, which included back-to-back losses to the Bombers, they probably wouldn't have found themselves in the position they were in on Saturday.

"Totally. I mean, that's part of it but I live in the reality, and one way or another, we are exactly where we're supposed to be. Of course, you wish that you won one or two of those, and it changes the outcome, but our steps are ordered the way that they are, and I believe, for good reason. It feels negative tonight because we really wanted to win this game. We've got work due tomorrow, so let's go," said Mace.

The Riders, who entered the game on a four-game winning streak, finished the season with a 9-8-1 record and will host the B.C. Lions in the West semifinal on Nov. 2. The winner of that game moves on to play the Bombers in Winnipeg on Nov. 9 in the West final.

The Stampeders, who finished last in the West with a 5-12-1 record, earned their first road victory of the season. It was a challenging season for the Stampeders and Calgary head coach and general manager Dave Dickenson liked how his team responded in Saturday's game.

"I do think we got good character on our team. I believe we have good culture; I do. I believe the guys work hard and they want to win. We just weren't detail oriented enough at this point we lost our confidence. So yeah, [our team] will change, certainly, but at least you finished on the right note," said Dickenson.

"Last week we played Hamilton. That was a tough one to swallow. I can't look at any one person or anybody that really played or performed like they wanted to, and then today, you can see a lot better. And certainly, the guys responded."

With the Winnipeg victory, the Riders made several roster changes, removing defensive back Rolan Milligan, running back A.J. Ouellette and receivers KeeSean Johnson and Samuel Emilus from the lineup. They also chose to start Shea Patterson at quarterback in place of veteran pivot Trevor Harris.

Patterson played most of the first half and struggled, completing just six of 13 passes for 62 yards. The Riders were held to 104 yards of total offence in the first half. Rookie Jack Coan replaced Patterson for the final possession of the first half and played the remainder of the contest for the Riders.

Calgary quarterback Jake Maier had a slow start, completing just one of his first seven passes. He got in a groove late in the first quarter, connecting with Clark Barnes on passes of 40 and 33 yards, respectively. The second Barnes reception went for a touchdown to give the Stampeders a 7-3 lead.

The Stampeders increased their lead to 14-3 midway through third quarter when Maier hit Cam Echols on a nine-yard touchdown reception.

On the first play of the fourth quarter Marken Michel hauled in a 67-yard touchdown pass from Maier, making the score 24-6.

In the fourth quarter, Coan threw his first CFL touchdown hitting Jerreth Sterns on a 19-yard scoring pass. A failed two-point convert left the score at 24-12.

Maier completed 19 of 26 passes for 293 yards and three touchdowns. Dedrick Mills had 128 yards rushing on 20 carries for the Stampeders.

Rene Paredes had two field goals for the Stampeders while Brett Lauther kicked two field goals for the Riders.

Demerio Houston, Julian Howsare and Justin Sambu each had a sack for Calgary. Jayden Dalke and Benoit Marion had sacks for Saskatchewan.