Only 2:22 remained in the third period when Zetterlund scored the game-winning goal with a direct shot during New Year's Day at home in the Canadian Tire Center.
It was the 26-year-old's tenth goal in 39 games in the NHL this season.
Ottawa had to struggle for the victory after a first period in which Washington dominated and took a 2–0 lead.
"We didn't get it done the way we wanted. But in the second and third periods we recovered and played like we wanted to win and wanted to be there. It shows the character of this team," Zetterlund said after the game, according to nhl.com.
