Ottawa has won three straight at home for the first time this season.
"It feels really good I think," said defenseman Erik Karlsson, who was on the ice for nearly 30 minutes. "We really wanted to win this game, and they came out pretty hard in the first.
"I think we stuck to it and we were confident that if we just did the things we needed to do we would come out successful."
The Senators again gave up the first goal, but a couple of highlight-reel goals and strong goaltending were enough to earn the victory.
Craig Anderson, who is riding a three-game winning streak, made 34 saves.
"We battled all night," he said. "We made some mistakes, but it's what happened after that. We battled hard, we back-checked hard, we found ways to keep guys from getting to the net. That's the difference in the game.
"I liked our fight and I liked our work ethic. That went a long way to getting us two points."
Joel Ward scored the lone goal for the Capitals (20-15-5), who have lost back-to-back games. Philipp Grubauer, in his fourth straight start, made 35 saves.
Ottawa took a 2-1 lead on Turris' 10th goal of the season 3:14 into the second period. He cut through the Washington defense and deked Grubauer to open up the left side of the net.
"I knew I got hooked, but I think it helped me fake the goalie out," Turris said. "I don't think (Grubauer) thought I would be able to get it to my forehand so it kind of faked him at the same time delaying it."
The Capitals pressed hard for the tying goal, but Anderson stopped all 14 shots he faced in the second period and 11 more in the third.
With just more than two minutes remaining, Anderson made a great glove save on Eric Fehr to preserve the lead.
"We had great chances to score goals but we didn't," said Washington's Alex Ovechkin, who is pointless in four games. "We hit crossbars, posts, and he makes a good save. Of course when you make a goalie hot, he's going to play hot."
MacArthur made it 3-1 with 34 seconds remaining after Karlsson gave him a wide-open net to snap his 10-game scoring drought.
"I saw he was there, and he hasn't scored in a couple games so I knew it was the right thing to do," Karlsson said of the passing play.
The Senators got off to a rough start in the first period as Ward opened the scoring on Washington's second shot of the game just 2:11 in. Ward's shot hit Anderson's stick and caromed into the net.
After that, Anderson played his best game of the season. He cited the Senators' penalty killing, shot blocking and play along the boards as keys to the victory.
"It's stuff that doesn't always show up on the score sheet like goals and assists do," he said. "It's those little things that make a difference in a game, and a lot of people don't realize that, but we definitely recognize it in the room."
Ottawa tied it at 13:49 of the first when Zibanejad and Cory Conacher put together a great passing play. They broke in on a 2-on-1 rush and completed a give-and-go that finished with a tap-in by Zibanejad.
Ottawa lost forward Chris Neil midway through the first period when he collided with Ovechkin. Neil was sidelined by a lower-body injury.
Senators coach Paul MacLean said it likely will sideline Neil for a bit. Neil will need to undergo further evaluation before it is known how long he will be out of action.
Ovechkin said he took the worst of the collision and believes the NHL should review the play, which went unpenalized.
"I think four guys out there didn't do their job. I think they started celebrating New Year's too early, right before the game," Ovechkin said. "They didn't see head shots on Neil against me.
"I felt like he was going to hit me shoulder to shoulder. I was ready for it, but he hit right in my head, right in my chin."
Ottawa C Jason Spezza and D Chris Phillips missed their second straight game because of lower-body injuries. D Eric Gryba was a healthy scratch. ... The Capitals are dealing with trade demands from a number of players, including G Michal Neuvirth, who was a healthy scratch. ... Washington C Brooks Laich missed his third straight game because of a strained groin. D Alexander Urbom was a healthy scratch.
Copyright by STATS LLC and The Associated Press
Arena: Canadian Tire Centre Location: Ottawa, Ontario
Referees: Brad Meier, Jean Hebert Linesmen: Mark Wheler, Pierre Racicot
Attendance: 20,193 (109.2% full)
Team Stat Comparison
Power Play Goals
Power Play Opportunities
Shots on Goal
Joel Ward (12)
Assists: Martin Erat, Jason Chimera
Mika Zibanejad (9)
Assists: Cory Conacher, Milan Michalek
Kyle Turris (10)
Assist: Bobby Ryan
Clarke MacArthur (12)
Assists: Erik Karlsson, Jared Cowen