BOSTON -- So how exactly did the Boston Bruins rally from a 4-1 deficit to fashion a dramatic 5-4 overtime win on hockey's biggest stage -- Game 7 of a Stanley Cup Playoffs series.

It depends on who you ask.

Toronto coach Randy Carlyle thought his team's gas tank hit empty after Nazem Kadri scored 5:29 into the third period for a 4-1 lead. He says his players didn't have the energy reserves to successfully navigate the 14-plus minutes of the contest.

How they did it: A look at the comeback

Hall of Fame coach and general manager Emile Francis once noted that, "This game is slippery. It's played on ice." Games like the Boston Bruins' comeback victory against the Toronto Maple Leafs on Monday night are what "The Cat" had in mind.

Toronto led Boston 4-1 in the third period of Game 7 in their Eastern Conference Quarterfinal series and appeared to be on the way to winning its first Stanley Cup Playoff series since 2004. Instead, the Bruins became only the fourth team in playoff history to overcome a three-goal deficit and the first to do it when trailing by three in the third period. Patrice Bergeron's overtime goal lifted Boston to a stunning 5-4 victory and into the conference semifinals against the New York Rangers.

Here’s a look at the timeline of Boston's comeback:

2:09 -- Former Bruin Phil Kessel quiets the TD Garden crowd by firing the rebound of James van Riemsdyk's shot behind Tuukka Rask to stretch Toronto's lead to 3-1.

5:29 -- Nazem Kadri scores the first playoff goal of his career, banging in the rebound of Kessel's shot off a 2-on-1 rush for a 4-1 lead. While the Maple Leafs celebrate on their bench, a few non-believers begin to trickle out of TD Garden.

9:18 -- The Bruins go 2 1/2 minutes after Kadri's goal without generating a shot. But Boston finally manages to generate some pressure, forcing Toronto goaltender James Reimer to make saves on Brad Marchand and Jaromir Jagr. But the Bruins keep the puck in the zone, Milan Lucic carries around the net and finds Nathan Horton in the left circle; he whirls and rifles a shot past Reimer to cut the deficit to 4-2, giving the Bruins and their fans a glimmer of hope.

18:38 -- Boston dominates play after Horton's goal -- Toronto goes more than seven minutes without a shot on goal -- but the Bruins can't get another shot past Reimer. Rask leaves for an extra attacker with less than two minutes to go. Zdeno Chara fires a slap shot from the right point that gets through traffic and forces Reimer to make a save. But he can't control the rebound, which Lucic lifts into the net to cut the deficit to one goal and get TD Garden rocking.

19:09 -- The Bruins leave Rask on the bench and keep their six attackers on the ice. They control the draw and get the puck into the zone. Bergeron, standing in the high slot, takes a pass from David Krejci and wrists a shot on goal. With Chara providing a 6-foot-9 screen in front of Reimer, the puck sails into the net to tie the game with 50.1 seconds left in regulation.

19:45 -- Boston nearly wins the game late in the third when Reimer can't control the rebound of Brad Marchand's shot. The puck slides into the slot, where Rich Peverley is facing a half-empty net, but hops over his stick. A few seconds later, the siren goes off and the game heads to overtime.

6:05 -- Both teams have chances in overtime before the Bruins work the puck into the Toronto zone. Lucic has a shot blocked by defenseman Jake Gardiner, but Boston maintains control and Tyler Seguin pumps a shot that Reimer stops. With Reimer and his defense scrambling, Bergeron races into the right circle, finds the puck and fires it past the helpless goaltender, triggering an eruption of sound in the Garden and sending the Bruins into the second round with a 5-4 victory.

-- John Kreiser

So instead of riding out the storm and pocketing a victory, the Maple Leafs allowed three goals in the final 10:42 of regulation to force overtime, which ended when Patrice Bergeron scored his second goal of the game at 6:05.

"Just trying to chew the clock, get the game down," Carlyle said of his team's mindset after delivering what seemed like the knockout punch to the Bruins. "You know they scored the one goal that gave them some life and we got it to a minute and a half and you knew the goaltender was going to be coming and we give up a goal that we thought, we still had a chance with the goalie out and they found a way to push one over the line. It just seemed like we ran out of gas."

It wasn't fatigue, Toronto captain Dion Phaneuf said. Rather, it was a five-minute loss of focus -- during which Milan Lucic and Bergeron scored sixth-attacker goals 31 seconds apart that tied the game at 4-4 with 50.1 seconds left in regulation.

"It's extreme disappointment," said Phaneuf, who was on the ice for the tying and winning goals by Bergeron. "It was a seven-game series that was extremely hard fought. Give Boston credit. They are a team that played an extremely hard series. We came into their building tonight, Game 7, and played 55 minutes of really good hockey. It's just extremely disappointing any time a year comes to an end, and this one is probably the toughest loss I ever had in pro hockey."

For Reimer, who had been brilliant for Toronto throughout this series, it was just luck -- or a lack of it -- for Toronto in the dying minutes of the game

"It's not like we were getting away from our game at 4-1," Reimer said. "They came with some pressure and some desperation and they were able to squeak a few lucky bounces in."

For Lucic, it was a matter of resetting the team's mindset and executing while staring elimination in the face. He said the club just decided to go for broke and that resulted in far crisper execution. The results were there for all to see.

On Nathan Horton's goal with 10:42 left in regulation, the Bruins left their own zone with speed and attacked the Toronto end cleanly in transition -- and, just like that, it was 4-2.

Lucic himself scored a 6-on-5 goal with 82 seconds left to make it 4-3. This time, he said the club worked on getting to loose pucks and funneling everything toward Reimer. The fact that he scored on the rebound of a point shot by Zdeno Chara is testament to the feasibility of that simple plan.

Finally, Bergeron scored another 6-on-5 goal to tie the game. He took a pass from David Krejci at the blue line and threaded a wrister past Reimer, using Chara as a perfect screening element.

"I can't really explain it. We got the bounces, we got the breaks," Lucic said. "Once we got that second goal, it felt like a weight was lifted off our shoulders. You know, especially on those 6-on-5 goals, we were able to win puck battles, settle it down and get the puck to the net and it paid off for us because you look at our 6-on-5s during the year, it usually ends up in the back of our net."

Instead, Boston got the goals it needed to force overtime, and it struck with a fourth straight goal to wriggle out of the most desperate of circumstances.

That, said coach Claude Julien, is a testament to the veteran core of this club, which won a Stanley Cup championship two seasons ago.

"They certainly keep you in check; I’m a tired coach, I can tell you that much," Julien said in describing the Jekyll and Hyde nature of his team. "Trying to really find a way to get these guys to give us what we want out of them, and we make it tough on ourselves. We’re being honest here, not being able to close it in Game 5; we’ve had trouble. We’ve always had trouble with the killer-instinct.

"But that’s maybe a fault of ours, but a strength of ours is the character you saw tonight."

In the end, the Bruins will take their character win into the second round against the New York Rangers with their dreams of a Stanley Cup championship still alive.

Toronto, meanwhile, is left to wonder what exactly happened down the stretch -- when its own dreams turned into nightmares as the parade of Boston goals grew longer and longer.

The answers won't be easy. They will, however, be painful.

"The low feeling you're feeling right now, that's in the top five of lows of your life," Reimer said in a near-silent visiting dressing room at TD Garden.

On a night when extra explanation was needed constantly to determine what had been witnessed, no further clarification was needed.