Dylan Cozens and Ryan McLeod also scored for the Sabres (16-21-5), while Ukko-Pekka Luukkonen provided solid goaltending with 35 saves.
Anton Forsberg stopped 17 shots in the defeat for Ottawa (19-18-3). The Senators returned to the Canadian Tire Centre after a nine-game road trip and nearly a month away, having vacated for the world junior hockey championship.
Their lacklustre performance left fans booing the home team, which is staring at a four-game losing streak (0-3-1). Ottawa has been outscored 15-4 during that stretch.
Quinn buried his first midway through the first period to open the scoring. He made it 2-0 later in the frame, taking a Peyton Krebs pass at centre ice as he stepped out of the penalty box before going bar-down for his seventh of the season.
A Nick Jensen turnover early in the second allowed Cozens to beat Forsberg. McLeod made it 4-0 midway through the period.
Senators: Failed to convert their chances and had too many defensive breakdowns.
Sabres: Capitalized on their opportunities and benefited from a couple good bounces.
Leading 3-0, the Sabres put the game well out of reach when McLeod benefited from an attempted pass deflecting off Thomas Chabot’s skate and into the net.
The Senators have gone 1-5-1 since Dec. 21, scoring an NHL-worst 1.67 goals per game during that span.
Senators: Head to Pittsburgh to take on the Penguins on Saturday.
Sabres: Host the Seattle Kraken on Saturday.
