Morgan Rielly scored the winner in the third period and added an assist as the Toronto Maple Leafs topped the Montreal Canadiens 5-2 in the first game of the post-Mitch Marner era Wednesday.Bobby McMann and Calle Jarnkrok also scored for Toronto before Auston Matthews and William Nylander added one each into the empty net. Anthony Stolarz made 27 saves in both teams’ opener to the NHL season. Nylander, John Tavares and Steven Lorentz also had two assists each.Oliver Kapanen, with his first NHL goal, and Zachary Bolduc replied for Montreal. Sam Montembeault stopped 23 shots.McMann opened the scoring just one minute in before Kapanen jumped on a turnover with Montreal killing a penalty. Bolduc scored his first with the Canadiens in the second after being acquired from the St. Louis Blues, but Jarnkrok tied things later in the period to set the stage for Rielly’s clincher.Marner declined to ink a contract extension with Toronto — the club he cheered on as a kid that then selected him No. 4 overall at the 2015 NHL draft — last season before the Leafs were forced into a sign-and-trade with the Vegas Golden Knights for the star winger that netted depth forward Nicolas Roy.Takeaways Leafs: Roy, Matias Maccelli and Dakota Joshua all made their debuts for Toronto, which will look to replace Marner’s minutes on the top line, power play and penalty kill by committee.Canadiens: Kapanen’s goal came in his 19th NHL game. The 22-year-old became the fifth player on record in franchise history to accomplish the feat while short-handed — and the first since Chris Chelios on Oct. 13, 1984.Key moment Leafs winger Matthew Knies was denied on a breakaway midway through the third, but stayed with the play and fed Rielly in front for him to bury a shot upstairs on Montembeault.Key stat The Leafs and Canadiens met in their season-opening game for the sixth straight season and 23rd time overall — the highest total in NHL history. The Vancouver Canucks and Calgary Flames are next with 12 curtain-raising contests.Up next Canadiens: Visit the Detroit Red Wings on Thursday.Leafs: Visit the Red Wings on Saturday.