Auston Matthews added his NHL-leading 14th goal for league-leading Toronto in the second game of three-game series in Toronto. Jake Muzzin had two assists.
''This was a huge win for us bouncing back from a tough loss,'' Kerfoot said. ''It's really big in a shortened season like this to stop that negative momentum. You don't want that creeping into minds or into your game.''
In the opener Monday night, Ottawa overcame a 5-1 deficit in a 6-5 overtime victory. The teams will wrap up the series Thursday night.
Brady Tkachuk scored for Ottawa, and Matt Murray made 26 stops.
Not long after a Toronto power play ended, Kerfoot fished a puck out of a scramble in front of Murray following Muzzin's initial shot for his third goal of the season.
Toronto opened the scoring at 4:32 of the second on Matthews' 13th goal in his last 12 games. Moments after Joe Thornton had one of his own waved off for the second time in the game - a high stick on this occasion - Matthews took a pass from Justin Holl and rifled a one-timer past Murray.
''There's nothing you can really do about those (disallowed goals),'' Matthews said. ''Once we scored there right after the high stick, the boys were saying, `The puck don't lie.'''
Tkachuk tied it with 1:22 left in the second for his fifth of the season and 100th NHL point.
''We were right there,'' Tkachuk said. ''It's a good sign we can hang right there with them.''
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