Jake DeBrusk scored for the Bruins (51-26-5), who had won four in a row and still had a chance to finish third in the Atlantic Division but will face the Carolina Hurricanes in the Eastern Conference First Round. Jeremy Swayman made 22 saves.
Game 1 of that best-of-7 series will be played at Carolina on Monday.
"We expect Carolina to be a difficult opponent," Boston coach Bruce Cassidy said. "They press, they're a great skating team, they check well. But we feel we can do the same things, so it should be a great series.
"A little bit is puck management and playing behind them because they like to press up and then winning some races. You don't have to win them all, but you have to win your share and you've got to defend well against them."
The Bruins opted to rest forwards Patrice Bergeron, Brad Marchand, David Pastrnak, Erik Haula and Taylor Hall, and defensemen Charlie McAvoy, Hampus Lindholm and Matt Grzelcyk.
"We love our lineup, we love everyone we have in that locker room, even guys who are out of the lineup," Boston forward Charlie Coyle said. "If there's injuries or whatever happens, you never know what's going to happen in the playoffs. We have guys come in, step up and step right in and make an impact, and that's what we need. That's what good teams have. We have a lot of depth that way. We're really confident and we're just itching to get going."
William Nylander scored twice and Erik Kallgren made 24 saves for the Maple Leafs (54-21-7), who finished second in the Atlantic and will face the Tampa Bay Lightning in the first round. Tampa Bay is seeking its third straight Stanley Cup championship.
Toronto will host Game 1 of that best-of-7 series Monday.
"It's a huge challenge for us," Toronto forward Jason Spezza said. "Exactly what we want, exactly what we need. We have a lot of respect for that team what they've done the last couple years. It's going to be a heck of a series."