Hergy Mayala caught his first career TD and the Stampeders lead the visiting Saskatchewan Roughriders 20-18 at the half.

The receiver caught an eight-yard strike from Bo Levi Mitchell in the battle for the top spot in the CFL’s West Division.

On a crisp night at McMahon Stadium, Mitchell is 12-of-17 passing for 141 yards, one major and one interception.

On the opening kickoff, Marcus Thigpen fumbled the ball but then picked it up and got the edge, running for 38 yards before being pushed out of bounds.

After a pair of eight-yard rushes on their first two plays, Cody Fajardo unloaded a deep bomb for Shaq Evans, who was wide open after Tre Roberson fell while running with him in coverage.

Roberson tried to recover and catch Evans but took a knee after the play and stayed there for awhile before slowly walking off the field. He did not return.

However, the ball went off Evans fingertips as he tried to catch it at the one-year line on what looked like surefire TD.

Saskatchewan settled for a single point after a 57-yard punt from Jon Ryan.

The Stamps got three points on their opening drive, Rene Paredes booting a 47-yarder to get the homeside on the board.

Things went much worse for Thigpen on his next attempt at catching a punt, as he reached out and got a hand on a bouncing ball after a high, short kick from Rob Maver, Jamari Gilbert grabbing the ball at a full gallop at the 28-yard line and running it in for his first career touchdown.

The Roughriders narrowed the gap when Nick Marshall picked off a Mitchell pass that was intended for Richie Sindani at the Saskatchewan 48-yard line, legging it untouched 62 yards for the Pick 6.

The Stamps then picked up another three points thanks to a 45-yard field-goal by Paredes.

On the eight-play drive that led to that, Eric Rogers caught a 19-yard pass but appeared to fumble the ball as he was tackled, Micah Teitz picking up the ball and running it into Calgary territory. However, the play was reviewed by the CFL Command Centre and Rogers was ruled down by contact.

The Roughriders took their second lead of the game with less than four minutes to play in the half, when William Powell punched in a three-yard TD run to cap 15-play, 91-yard drive.

On Saskatchewan’s next drive after the go-ahead Mayala major, Royce Metchie picked off Fajardo giving the Stamps the ball at their own 35-yard line but they weren’t able to get any points out of it.

The Roughriders got another three points on their final drive of the half.