The Marlboros were defeated in the playoffs that year, and, like in Port Arthur, Lewicki was invited to join another team on a playoff run. This time it was the Marlboros' senior team, in competition for the Allan Cup. The Marlboros defeated the Kitchener-Waterloo Dutchmen, then the Cornwall Calumets, the Sault Ste. Marie Greyhounds and the Sherbrooke Saints to advance to the 1950 Allan Cup final against the Calgary Stampeders. Lewicki would be named the MVP for the series as the Marlboros defeated Calgary 4–1. Lewicki scored 42 points in the 17 playoff games.