REGINA -- Defensive lineman Zack Evans and defensive back Ed Gainey scored touchdowns and Brett Lauther kicked four field goals as the Saskatchewan Roughriders beat the visiting B.C. Lions 35-16 on Saturday.

The Roughriders clinched a home playoff game for the first time since 2013 with the win and the Lions guaranteed that they would cross over to the East Division for the post-season.

Tre Mason also scored a touchdown for Saskatchewan (12-6), a seven-yard run in the second quarter that gave the team a 13-0 lead.

The win also bumped Roughriders into a tie with the Calgary Stampeders (12-5) for first place in the West Division. The Lions, already having clinched a playoff berth, are 9-8.

The Riders have a bye next week, while Calgary will visit the Lions in the final week of the regular season.

Saskatchewan's week off may help answer questions about the health of quarterback Zach Collaros.

Collaros was on the receiving end of a hard hit to the shoulder and head area from Lions defensive end Odell Willis. Collaros stayed in the game and finished the drive, one that ended in Mason's 10-yard touchdown run.

Collaros did not return to the game after that score early in the second quarter with his team up 13-0. Collaros completed five of eight pass attempts for 52 yards. Brandon Bridge and David Watford split time under centre for the remainder of the game.

The Riders were without Collaros for four games early in the season after he suffered a concussion in Week 2. The team had a 2-2 record without their starter.

Saskatchewan's first defensive touchdown was set up when Willie Jefferson stripped B.C. quarterback Travis Lulay near the Lions goal line. Evans scooped up the loose ball and plunged into the end zone for the score.

Gainey's 41-yard interception return for a touchdown in the fourth quarter tied a CFL record for defensive touchdowns in a season (11). That score gave the Riders a 32-9 lead.

Lulay threw a 44-yard touchdown to Bryan Burnham in the third quarter for B.C.'s first touchdown. Lulay completed nine of 20 pass attempts for 94 yards and one touchdown. He was intercepted twice. Jonathon Jennings replaced Lulay in the fourth quarter.

Cody Fajardo also scored for the Lions on a one-yard run in the fourth quarter.

The Riders were 3-4 in August and have rattled off an 8-2 record since. B.C. is 6-2 in its last eight games and won three straight heading into Saturday's game.