Dekker remained with the Redskins for only one season. In 1954, he joined the Hamilton Tiger-Cats of the Canadian Football League. In nine seasons at Hamilton, Dekker played in the Grey Cup championship contest five times, winning once in 1957. He was elected to the All Eastern/All Western All‑Star team four times and tied a Grey Cup record for the longest completed pass with a 90‑yard touchdown reception in the Tiger‑Cats' 21‑14 overtime loss to the Winnipeg Blue Bombers in the 1961 Grey Cup game. He died before seeing the record broken in the year after he passed. Dekker retired from professional football following the 1962 season.