Eric Rogers hauled in an Arbuckle pass for a 19-yard touchdown on the final play of the third quarter to extend Calgary’s lead to 22-10.
On the ensuing Saskatchewan possession, Tre Roberson picked off a Cody Fajardo pass and returned it 48 yards for a touchdown. Rogers added a two-point convert to put Calgary up comfortably 30-10.
The Stampeders defence bottled up Fajardo and the Riders offence in the fourth quarter.
Calgary improved to 2-1. The Riders fell to 1-3.
Ka’Deem Carey on a two-yard run and Reggie Begelton — a 76-yard reception — scored Calgary’s other touchdowns.
Carey and Terry Williams combined to rush for 122 yards.
Fajardo scored Saskatchewan’s only touchdown on a one-yard run in the third quarter. He was replaced with rookie backup Isaac Harker early in the fourth quarter.
Arbuckle finished 19-of-22 for 262 yards and two touchdowns with no interceptions.
He came off the bench and replaced an injured Bo Levi Mitchell last week late in the fourth quarter, rallying the Stampeders to a comeback victory over the B.C. Lions.
Fajardo struggled on Saturday. He completed 9-of-15 pass attempts for 89 yards and was intercepted twice. Five days previous, he threw for 430 yards and two touchdowns in a 32-7 win over the Toronto Argonauts.
Rene Paredes kicked three field goals for Calgary. Reggie Begelton had four catches for 102 yards.
Naaman Roosevelt led Saskatchewan with five catches for 66 yards.
The Stampeders led 15-3 at halftime.
The Riders narrowed the gap with their first drive of the second half. Loucheiz Purifoy returned the opening kickoff 69 yards to the Calgary 30-yard line. Four plays later, Fajardo scored.
Calgary will travel to Hamilton to play the Tiger-Cats on Saturday. The Riders are on a bye week before they return July 20 to host the B.C. Lions.