In 1941–42, Smart moved with the Sr. Canadiens to the Quebec Senior Hockey League (QSHL). Affiliated with the Montreal Canadiens of the National Hockey League, Smart was called up to the NHL in 1943 and, on January 14, became the first player in league history to score a hat trick in his NHL debut (this feat was later matched by Réal Cloutier of the Quebec Nordiques in 1979, Fabian Brunnström of the Dallas Stars in 2008, and Derek Stepan of the New York Rangers in 2010). He completed the season with 5 goals and 2 assists in 8 games – the lone NHL stint of his career. 