Colin Greening scored the winner at 8:43 of the third period to lift the Ottawa Senators past the Toronto Maple Leafs, 3-2, at Air Canada Centre.
Zach Smith and Jim O'Brien scored for the Senators, who did not dress Jason Spezza, Bobby Ryan and Erik Karlsson in the first of three games in three nights. Robin Lehner made 26 saves.
James van Riemsdyk and Dion Phaneuf scored for Toronto in a game tied 1-1 going into the final period. The Leafs almost tied it up in the dying seconds with a wild flurry and goalie James Reimer on the bench.
"Last year, Toronto had us beat most of the games, and it's a rivalry, so it's always nice to beat them," Lehner said.
Reimer, who's battling Jonathan Bernier for the starting job, made 34 saves.
"I was the starter here last year and I had no intention of giving up whether they brought in Bernier or Lundqvist or someone who'd never played an NHL game before," Reimer said.
Said coach Randy Carlyle: "He made big-league stops, played very well."