BROSSARD, Quebec — Nobody has called 911 yet. Can this possibly be a Boston Bruins-Montreal Canadiens playoff series?

With Boston holding a 3-2 lead in the first-round series heading into tonight’s game in Montreal, play between the two teams has been so close that neither team is willing to risk giving the other a needless power-play opportunity.

“It’s playoff hockey,” Canadiens forward Travis Moen said following the team’s practice Monday at its suburban rink complex. “No team wants to put their team down, you know, spend a lot of time in the penalty box, so it’s physical but it’s clean.”

The dangerous – not to mention illegal – use of the emergency telephone number by Canadiens fans in the wake of Zdeno Chara’s devastating hit of Max Pacioretty on March 8 was an example of the rivalry spilling over into the real world.

While Montreal police deplored the irresponsible use of the 911 number, they did begin an ongoing investigation into the incident, which left Pacioretty with a severe concussion and a broken neck vertebrae.

Five games into this 33rd playoff series between the Bruins and the Canadiens, there is little to separate the margin of play between the two bitter rivals. Each team has scored 12 goals in the series, making Boston’s one-game lead that much more valuable.

Buoyed by two straight overtime wins, the Bruins can end the series with a fourth straight victory tonight. If Montreal comes out on top, it’s back to Boston, where the Canadiens have won two of three, for a decisive Game 7 on Wednesday.

With so much at stake, the focus is squarely back on the ice.

“Every game has been down to the wire so neither team can afford to do something stupid,” Canadiens left wing Mathieu Darche said. “I think they know our power play is pretty effective so they don’t want to take those chances to put us on the power play, and the same thing for us. Even if they haven’t scored on the power play, at one point it’s the law of averages, they’re bound to get one. The playoffs are about discipline, too.”

Andrew Ference was fined $2,500 for making an obscene gesture toward the Bell Centre crowd in Game 4. The Bruins’ defenseman apologized afterward, claiming that he was the victim of a wardrobe malfunction which caused the middle finger of his glove to rise above the others when he pumped his fist to celebrate a goal.

Aside from two heat-of-the-moment fights, there has been little of the dirty play that has blemished many of the other first-round series.

“Maybe, hopefully, we got it all out of the way during the regular season,” said Boston forward Gregory Campbell, the son of NHL disciplinarian Colin Campbell.