MONTREAL - Weston Dressler and Wes Cates scored touchdowns and the Saskatchewan Roughriders jumped on a Montreal attack missing injured quarterback Anthony Calvillo to beat the Alouettes 27-24 and pick up their first win of the season Sunday night.

Saskatchewan (1-3) handed the Alouettes (3-1) their first defeat before a not quite sold out crowd of 24,434 at Percival Molson Stadium.

Calvillo left midway through the second quarter with Saskatchewan leading 14-7.

The 18-year veteran was taken down by former Alouette Dario Romero as a rushed pass was picked off by linebacker Sean Lucas. He went to the dressing room with an eye injury. He returned to the bench, but didn't play due to blurred vision.

With Adrian McPherson behind centre, the Montreal offence all-but stalled for more than two quarters. But the crowd was on its feet as McPherson led a late drive capped by a nine-yard TD pass to Brian Bratton that close the gap to seven points with 4:11 left to play.

The Riders looked to have put the win away with 1:21 left when Eddie Johnson booted his fourth field goal of the night from 36 yards to give Saskatchewan a 27-17 lead, but it only set the stage for a wild ending.