The West's road to the Grey Cup will go through Regina.
The Roughriders will now host the West final for the first time since 2009, and only the third time in the last 45 years.
Saskatchewan scratched Fajardo from the regular-season finale because of an injury, forcing rookie Isaac Harker to start in his place. Harker acquitted himself well under the circumstances, completing 23 of 28 passes for 213 yards with no touchdowns or interceptions.
Things appeared to be on the verge of collapse for the home side in the third quarter after Edmonton scored 13 unanswered points to grab the lead. But Saskatchewan's defense stood tall from there, holding the Esks off the board in the fourth and allowing kicker Brett Lauther - who missed four of six field-goal attempts - to redeem himself late with the winning boot.
Cameron Judge then clinched the division for the Riders with a 29-yard pick-6.
The East Division playoffs were already locked in coming into Week 21. Edmonton will cross over and visit the Alouettes in Montreal next week, with the winner traveling to Hamilton for the East final.