Ilya Samsonov made 34 saves for the Maple Leafs (42-22-9), who have won four of their past six games. Toronto is third in the Atlantic Division, six points behind the Florida Panthers and four ahead of the Tampa Bay Lightning.
"'Sammy' was fantastic," Toronto captain John Tavares said. "No doubt he was our best player. We defended hard and we competed. Obviously, it wasn't our best game. We didn't carry the play as much as we wanted. … But he led the way in how he competed and shut them down when they created some opportunities."
Ukko-Pekka Luukkonen made 19 saves for the Sabres (35-35-5), who have lost five of eight. Buffalo is seven points behind the Philadelphia Flyers for the second wild card into the Stanley Cup Playoffs from the Eastern Conference.
"I mean, it definitely gets frustrating after a while," Buffalo center Dylan Cozens said of not scoring. "You get tons of chances, and the goalie just stands on his head. Got to find a way to bury some of those. I've got to find a way to bury some of those, and our power play's (0-for-6) got to get a couple."
Tavares, playing in his 1,100th NHL game, gave Toronto a 1-0 lead at 4:58 of the first period. William Nylander sent a backhand centering pass inside the blue line to Tavares, who took it to the high slot for a wrist shot that beat Luukkonen glove side.
"I guess a good omen for me, considering the No. 11 (Tavares' uncle, former lacrosse player Jon Tavares) that wore that I came to watch lot as a kid," Tavares said. "So pretty cool to hit 1,100 in a game playing here. You don't think about it too much in the moment, but obviously I'm really fortunate to have a lot of great people around me, played with a lot of great players, coaches, teammates, so I just want to keep it going."