The Montreal Canadiens flag will be flying in front of Boston City Hall after Montreal Mayor Denis Coderre won a bet with Boston Mayor Marty Walsh that the Habs would win against the Bruins.

The Habs defeated the Boston Bruins 3-1 on Wednesday in Game 7 of their NHL playoff series, eliminating Boston from the playoffs.

While Bruins fans lick their wounds today, Walsh has a bet to fulfill.

The mayors of the rival teams' hometowns bet that whoever lost the series would have to wear the other town's jersey and fly the team's flag at city hall for a week. The losing mayor also has to visit the winning mayor's city as part of the deal.

Walsh said he plans to make good on the bet, just as soon as Coderre sends him a flag and a jersey in the mail.

The Boston mayor joked the flag will be up above city hall for about 10 seconds. 

But he said the most difficult part of the bet will be wearing the Canadiens jersey.

"That's going to be a tough one for me," he said. 

Coderre is currently in Europe on a cultural and commercial mission. He has been following the series, however, and today tweeted that he'll be in touch with Walsh to work out the logistics of their agreement. 

5 post-game revellers arrested in Montreal

Many Habs fans were recovering on Thursday from a long night of celebrating.

Habs reveller arrested

A total of five people were arrested on Wednesday evening, as Montreal's downtown streets filled with celebrating Habs fans. (CBC)

The Habs were on the road for Game 7, but Montrealers still came out to support their team, filling the Bell Centre and flooding the streets of downtown Montreal.

Montreal police dressed in riot gear were prepared for the crowds and kept the celebrations under control.

In the end, only a handful of people were arrested and the streets were mostly empty by 1 a.m. ET.

Montreal police Const. Raphael Bergeron said police arrested a total of five people — three were ticketed for bylaw infractions, and two for assault on a police officer.

Several more people were handcuffed and taken away by police, but released later without conditions.

Eastern Conference tickets on sale

The Canadiens will advance to the Eastern Conference final against the New York Rangers.

The first game in the series is set for Saturday at 1 p.m. at the Bell Centre.

Tickets for games one, two, five and seven in Montreal went on sale at noon today.