OTTAWA -- With a shutout at stake and a two-goal lead to protect, Chris Mason had a few anxious moments after hearing the ring of a puck striking metal behind him twice on the same play.
"You don't love hearing it, but when you see the puck squeeze out the other side it's a good feeling," said Mason, who got his 23rd career shutout.
"We've earned those breaks here, so that was very fortunate and I'm thankful for that."
Craig Anderson, who was selected as the NHL's first star of the week earlier in the day, stopped 33 shots for the Senators, who ended a four-game winning streak.
Ottawa, which was shut out for the first time this season, lost in regulation for the first time in 10 games (8-1-1).
"That says a lot about the game that we played," Mason said. "I thought we've been looking for that game for the last couple of weeks. We're a fairly low-scoring team and it seems one or two breakdowns have cost us lately, and I thought tonight the guys just did a wonderful job and we were able to have a great third period."
The Senators, who returned from a 3-0 trip, go right back on the road. Ottawa begins its second six-game trip of the season Tuesday night in Toronto.
"We're looking forward to it," Senators coach Paul MacLean said. "It's a great opportunity to get back and play. We're playing lots of games and we're going to get a chance to get right back in the saddle and get ready to go, and that's what we're going to do."
Bogosian missed his third straight game because of a lower-body injury. Byfuglien has been sidelined for nine games with a knee injury.
Slater scored his first goal in seven games since returning from an upper-body injury that sidelined him for a pair of games. He tipped Chris Thorburn's shot past Anderson for his eighth goal.
Enstrom scored his second goal -- his first since Oct. 19 -- to put Winnipeg up by two 6:48 into the second. The Swedish defenseman took Kyle Wellwood's pass and drove a slap shot along the ice through Anderson's pads while Winnipeg captain Andrew Ladd jumped in front of the Ottawa goalie as he provided a screen.
"We got a four-man rush up the ice and I was able to get it to Welly," said Ladd, who drew the secondary assist. "He made a great pass to Toby and I kind of just tried to follow in front and get a screen, and luckily enough it went in."
Mason's closest call before the two shots off the crossbar came 5:14 into the third. A video review confirmed that he kept the puck from crossing the goal line after Ottawa captain Daniel Alfredsson's shot off the end boards bounced back toward the net off Winnipeg defenseman Mark Stuart's left skate.
"I was about 99 percent sure that it didn't go in," Mason said.
"Not much to say about it right now," Karlsson said. "I think he's not going to hit me at all and then he goes for my head with his stick. It's a cheap hit. It's over now -- I don't care about it and he got to pay for it."
Ottawa defenseman Matt Carkner and Stuart got fighting majors.
The original Winnipeg Jets' last win over Ottawa was on Feb. 8, 1996, a 6-2 victory at the old Winnipeg Arena. ... The league's third star one week earlier, Anderson took the top honor Monday after going 3-0 with a .970 save percentage, including his first shutout of the season.