Scrivens was especially busy in the third period, when he turned aside 11 Senators shots to preserve the Leafs' fifth victory in six games.
Frazer McLaren's first-period goal stood as the game's only score until Tyler Bozak made it 2-0 8:32 into the third period.
John-Michael Liles added an empty-netter to seal the victory.
Craig Anderson stopped 26-of-28 shots for Ottawa, which fell to 2-5-1 in February.
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