MONTREAL - Even a major penalty and game misconduct to star defenceman P.K. Subban could not hold back the Montreal Canadiens.

The Canadiens proved that late-season goaltending sensation Andrew Hammond is human with four goals in the second period of a 4-3 victory over the Ottawa Senators in the opening game of their best-of-seven NHL Eastern Conference playoff series on Wednesday night.

Montreal, boosted by a raucous crowd of 21,287, had the upper hand for most of the game and outshot Ottawa 39-33, but nearly threw it away on a first-period own goal by defenceman Andrei Markov and Subban's controversial slash to the hand of Senators scoring ace Mark Stone in the second.

The incident will amp up the emotion heading into Game 2 on Friday night.

It left Ottawa demanding that Subban be suspended and Montreal coach Michel Therrien saying it was no more than a minor penalty. It is sure to be looked at for league discipline.

"He had been doing it a couple of times… he tried targeting me a couple of times in the first period off faceoffs," said Stone, who went into his first NHL playoff game on a nine-game points streak.

He added that a suspension would be "up to the league. Obviously it was a pretty big hack. Looked like he wanted to hurt me. There was some intent there."

"I agree it was a slashing penalty but I don't agree that it deserved five minutes," countered Therrien.

After Milan Michalek got credit for a goal Markov pushed past Carey Price in the first frame, a wild 30-second span in the second turned what had been an uneventful opener into controversy and a spate of goals.

Torrey Mitchell and Tomas Plekanec scored 15 seconds apart at 7:53 and 8:08, but only six seconds later, Lars Eller was sent off for high-sticking. Only nine seconds after that, Subban took a chop at Stone's hand the Ottawa forward went down to the ice in apparent pain, then rushed to the dressing room for treatment.

The officials slapped Subban, despite the former Norris Trophy winner's claims that Stone embellished his injury, with a major and a game misconduct.

During the five-minute power play, part of it with a two-man advantage, Ottawa scored twice through Kyle Turris and Mika Zibanejad, but Montreal got a short-handed goal from Eller.

Brian Flynn got the winner at 17:17.

Ottawa coach Dave Cameron wants either a suspension or retaliation for Subban's slash.

"I think it's an easy solution: you either suspend him or one of their best players gets slashed and just give us five," he said.

Stone returned shortly after the incident, but then left again late in the second period, only to return midway through the third. Cameron said only that he is "not 100 per cent."

The coach was also concerned about "sloppy" puck handling and passing by his team.

Without Subban, the remaining five Canadiens defencemen adjusted and held off Ottawa the rest of the way.

"Losing a player, playing long stretches on the penalty kill, we didn't get any calls for the first 50 minutes or so, that's strong of us," said Eller.

Late-season acquisitions Flynn and Mitchell, for their first goals as Canadiens as the team's third and fourth lines, excelled.

Notes _ A moment of silence was held before the game for Senators assistant coach Mark Reeds, who died this week of cancer at 55. . . Canadiens scoring leader Max Pacioretty sat out with an upper body injury but may return for Game 2 on Friday. . . Michalek was back for the first time since he had an upper body injury March 21.