BOSTON - An ineffective power play and a stagnant attack ruined the Flyers' season opener Wednesday night at TD Garden.

So did Chris Kelly.

With 1 minute, 51 seconds left in regulation, Kelly's goal gave the Boston Bruins a 2-1 win before a frenzied crowd.

Adam McQuaid's shot appeared to graze goalie Steve Mason's blocker and fluttered into the air before dropping near the crease, where Kelly tapped it into the net to snap a 1-1 tie.

"He broke his stick," Mason said of McQuaid's shot, "and it threw the timing off. The thing that threw me off the most, two guys skated in front and I lost sight of the puck . . . and it landed right in the crease and they were able to put it home."

The Flyers have lost three straight season openers for the first time since 1991.

The Flyers tied it with 15:41 remaining when Sean Couturier, stationed in front, tipped in Jake Voracek's spin-around pass from the right circle.

With 6:01 to go, Zac Rinaldo went to the penalty box for slashing, but the Flyers did a great job of not allowing the Bruins to get set up during the power play.

"When you're two minutes away from at least getting one point, it's [tough]," Mason said after he made 31 saves. "You can't lose hockey games in the last five minutes of a game. You really have to shut things down. They got a fluky play there. The guy breaks his stick and the puck changes all its momentum and it gives the guys the opportunity to get in front and create a screen."

The Flyers, who host New Jersey in their home opener Thursday night, had few good scoring chances and rarely tested Boston goalie Tuukka Rask (19 saves). They were 0 for 3 on the power play, totaling just four shots in those six minutes.

"We were just a little bit too much on our heels," coach Craig Berube said.

"The first two periods, it was like we were scared to make plays," captain Claude Giroux said. "I don't know about the other guys, but I would get the puck and I didn't get the confidence to make a play . . . I need to relax, play the game."

Giroux had a rough night. He managed just one shot and was 4 for 21 (19 percent) on faceoffs. He was 2 for 12 against Patrice Bergeron, who was 18 for 23 overall.

Boston, the Eastern Conference favorite, took a 1-0 lead on Reilly Smith's first-period power-play goal.

The Flyers were 20th in the NHL in goals allowed last season, and Berube says that can be improved by playing smarter, more disciplined hockey.

Translation: Reducing penalties is a must.

Midway through the first period, however, Rinaldo went to the box for high-sticking Torey Krug, and it set up Smith's goal 55 seconds later.

All four Flyers penalty killers dropped down deep to the right side, and Carl Soderberg sent a pass to a wide-open Smith, who beat a helpless Mason from the left circle.

The Flyers led the league in a dubious category last year - most penalty minutes. Rinaldo had, by far, the most on the team with 153.

With 9:08 left in the second, Luke Schenn defended Rinaldo after the Flyers winger was checked into the boards by two Bruins. Schenn and Bobby Robins, who was making his NHL debut at age 32, got into a long, close bout.

Less than two minutes later, the Flyers got their second power play but managed just one shot, though tip-in attempts by Vinny Lecavalier and Wayne Simmonds went just wide. Boston had five clears during the power play.

"I think we worked hard all game long, but we have to simplify our game," said Simmonds, who said the Flyers had "jitters" early in the game. "We weren't taking shots, and when you're trying to make that extra [pass], that's what happens."

Boston played without top-line center David Krejci, who was sidelined with an unspecified injury.