BOSTON - The Flyers never tried to hide it. They knew what a win in Boston on Saturday afternoon would mean to their playoff chances.

It would mean two critical points against the team with the inside track to the eighth and final playoff spot in the Eastern Conference. In their bid to catch Boston, the Flyers also must hurdle Florida and Ottawa, and the Bruins and Senators each carry two games in hand.

The Flyers had the lead late in regulation at TD Garden, but the Bruins tied it with 14.1 seconds to play before winning, 3-2, in overtime. Instead of drawing within two points of Boston with a regulation win, the Flyers slipped to five points back.

The Flyers cashed in an extended stay in the offensive zone for their first lead late in regulation. Chris VandeVelde redirected a Nick Schultz blast with 4 minutes, 30 seconds remaining as the visitors took their first lead of the afternoon.

But that elation gave way to disappointment and, ultimately, devastation. Boston forward Brad Marchand scored the equalizer with 14.1 seconds to go in regulation and the game-winner 3:52 into overtime.

"I'm done with this game," said Flyers coach Craig Berube, his stoic complexion etched with frustration. "We got a point - should have had two, but it didn't happen. So, got to go to Jersey and get two points there."

"It's a tough defeat," VandeVelde said, "but there's still time; I mean there's games, but it's getting down there. We've got to start winning games and doing the right things and holding on to wins."

It appeared the Flyers (28-25-13) would hold on for the win, a 2-1 edge standing strong with seconds falling off the clock, until Wayne Simmonds was called for tripping at 17:57 of the third period.

Down by a goal, Boston (33-22-10) elected to yank goaltender Tuukka Rask (29 saves) for the extra skater, giving the Bruins a six-on-four advantage.

Steve Mason (34 saves) was masterful while facing mounting pressure on the penalty kill. He turned aside a slapshot by Ryan Spooner at the backdoor, the puck floating through the air before trickling just wide of the far post.

Milan Lucic then tested Mason from the high slot, using traffic and redirection to his advantage. Mason was up to the task, flashing his left pad in making a shoestring save.

But Mason could do little to divert Marchand's tying goal. Camped in front of the crease, Marchand redirected a shot from Dougie Hamilton at the right point, the puck finding its way inside the left post.

The best opportunities of the extra period went to the Flyers, most notably a three-on-one opportunity with Luke Schenn, Pierre-Edouard Bellemare, and Jake Voracek churning up ice. Bellemare elected for the shot as Bruins defenseman Torey Krug blocked the passing lane, but Rask successfully guarded the near post.

A minute later, Voracek again broke for goal, this time a breakaway bid on Rask. The 25-year-old skated across the slot and threw a shot across his body, but Rask deflected it wide.

The visitors were rushing up ice when they fumbled possession in the neutral zone, with former Flyer Max Talbot initiating the counter for Boston. He fed Marchand, who raced through the left wing before cutting inside, flicking a backhanded bid on goal as he drove through the slot.

Flyers defenseman Michael Del Zotto hit the deck to block the shot, but the puck instead deflected off his skate and up over Mason's right shoulder.

"It's an unfortunate bounce," Mason said. "They found a way to win, and we found a way to lose the two points here, and that hurts."

After watching the puck reach the back of the cage, Simmonds shattered his stick off the left post. Sean Couturier raised his stick high and slammed it off the ice. They knew what that goal meant.

One step forward, two steps back.

Manning recalled. The Flyers recalled defenseman Brandon Manning from the AHL's Phantoms after the game. Del Zotto injured his foot blocking a shot and was not moving well on the ice afterward.

Staff writer Sam Carchidi contributed to this article.