Mika Zibanejad gave Mike Hoffman the opening he needed to help keep the Ottawa Senators alive.
With Zibanejad screening Montreal goalie Carey Price, Hoffman scored midway through the third period and the Senators beat the Canadiens 1-0 on Wednesday night.
"We need to get bodies in front of him (Price) and make it hard for him to save it," Hoffman said. "More times than not if he sees the puck he's probably going to save it. Mika did a great screen for me there and if he wasn't there it would probably not go in."
Craig Anderson made 28 saves to help the Senators' cut Montreal's lead to 3-1 in the Eastern Conference first-round series. Game 5 is Friday night in Montreal.
"We weren't going to win four games here tonight," Hoffman said. "It's one. We're moving on to the next one now."
Senators coach Dave Cameron moved Hoffman from the fourth line to the second unit with Zibanejad and Bobby Ryan during the first period. It paid off in the third when Cody Ceci kept Tom Gilbert's clearing attempt in at the point and fed the rookie in the left circle for quick shot that beat Price at 9:05.
"It was a big hockey game," Montreal coach Michel Therrien said. "It was very close. The two teams played very hard. They got the last word tonight, but we have no reason to be embarrassed about our performance. I think we worked very hard as well."
It was the fourth straight game the Senators scored first, but this time, the Canadiens didn't answer. An anaemic power play that has gone 1 for 16 in the series hasn't helped their cause.
"They came out with that urgency tonight," Canadiens forward Max Pacioretty said. "They were the better team in the third period tonight and you have to give them credit."
Price stopped 31 shots for the Canadiens.
Anderson, who made 47 saves in his series debut in Game 3, was strong again for the Senators. He sprawled to force Brandon Prust to slam the puck against the side of the net during a short-handed breakaway late in the second.
"I think it's just a matter of willpower," Anderson said. "That's what it comes down to, just sheer determination to go out there and do the job. I had a lot to prove after sitting out for so long and being out with injury. You just want to come back and do your best and that's what I'm trying to do."
Ottawa had the better chances on two second-period power plays, with Price stoning Hoffman from the doorstep and then robbing Clarke MacArthur from the slot.
Midway through the second period, Ottawa was on the wrong end of a rarely called faceoff violation penalty. After Zibanejad was tossed out of the faceoff circle, Hoffman knocked the puck out of the linesman's hand before the puck was dropped. Two false starts by one team drew the penalty.
Only four teams have come back to win when trailing 0-3 in a series: Toronto in 1942, the New York Islanders in 1975, Philadelphia in 2010 and Los Angeles in 2014.
Notes: Ottawa injected some speed into the lineup with Zach Smith at fourth line center, replacing David Legwand. Chris Neil played a second game in place of Alex Chiasson. ... With Nathan Beaulieu out with an upper-body injury, Montreal dressed Greg Pateryn on defense.