Dickenson began the 2005 season embroiled in a quarterback controversy with Printers, who was named the 2004 CFL Most Outstanding Player. Dickenson emerged as the starter, and was instrumental in leading the Lions to an 11-0 start (where he played in 9 of the 11 games), en route to a 12-6 season finish. Dickenson set an all-time CFL record with a passing efficiency mark of 118.8. He fell just short of the attempts required to set a further mark with a 74.0% completion rate, due to 4 games missed because of a concussion. Dickenson was named CFL Player of the Month for both July and September, and was Player of the Week twice.