The Florida Panthers stunned the Boston Bruins with a 4-3 overtime win in Wednesday's Game 5, defiantly avoiding what could have been the first elimination of the Stanley Cup playoffs.

Matthew Tkachuk's goal at 6:05 of overtime gave new life to the Panthers, who had dropped consecutive games at home -- games in which Boston was without its top two centers -- to fall behind 1-3 in the best-of-seven series.

"We were supposed to get swept this series, right? Everyone was saying," said Tkachuk, who had two points in the win. "I don't think anybody really gave us a chance after losing two games in a row at home. Coming here, it just seemed like the series was over before the game even started.

"Now they're coming down to Florida. We know there can't possibly be a Game 7 in their mind right now, and everybody here in Boston's minds. So it's up to us to see you guys back here in a few days."

Game 6 is Friday night.

Boston entered the postseason as the top seed in the Eastern Conference after setting new NHL records for wins (65) and points (135) in a single season. Florida was the second wild-card team in the East.

The Bruins failed to close out the series due to a few uncharacteristic miscues, including on the game-winning goal in overtime.

Goalie Linus Ullmark had a miscommunication with his defenseman and turned the puck over to Florida's Carter Verhaeghe, whose quick shot Ullmark kicked to the slot. Tkachuk collected the puck and, with Ullmark on his back, maneuvered around the Bruins defenders to score the game winner.

"I thought we had really good offensive zone pressure. We tried to move the puck over to the defenseman but we had made a change so the puck went all the way down. We just had a mishandle on our goalie/defenseman communication on the puck and it ended up getting jacked into our net," Bruins coach Jim Montgomery said.

The Panthers' other win in the series was a 6-3 victory at TD Garden in Game 2.

"We tend to make big mistakes right now. I don't know why, but the last two games at home we don't manage the ice or manage the puck, it's one of the two," Montgomery said.

The Panthers took the lead at 8:26 of the first period on another uncharacteristic turnover by Boston. Forward Tyler Bertuzzi sent the puck in front of his own net, where it was intercepted by Verhaeghe. He sent a pass from behind the goal line to a cutting Anthony Duclair, who smacked it down to the ice and into the net.

"For us to come out with the start we did speaks a lot about our team, our preparation and our belief in each other," Tkachuk said.

The Bruins tied the game on the power play at 2:27 of the second period. With Sam Bennett in the box for holding, defenseman Charlie McAvoy found Brad Marchand alone in front of Sergei Bobrovsky. The goalie saved the initial shot but Marchand's second effort knotted the game at 1-1.

But with 1:08 left in the second period, Florida struck again thanks to Verhaeghe. He found Bennett in the slot for his third goal of the playoffs.

The game marked the return of Bruins captain Patrice Bergeron, who missed the first four games of the series after suffering an upper-body injury in the team's regular-season finale at Montreal on April 13. Boston continues to be without second-line center David Krejci, who missed his third straight game.

Bergeron made his presence felt at 4:33 of the third period, tipping home a Marchand pass for a power-play goal. But Sam Reinhart responded just 41 seconds later with a power-play goal of his own, after Boston's Jakub Lauko took a holding penalty on Tkachuk just 6 seconds after Bergeron's goal. Tkachuk assisted on the Reinhart goal to make it 3-2.

The Bruins roared back to take the lead thanks to another strong play by Taylor Hall. After defenseman Brandon Carlo fired the puck from the left post, Hall collected the rebound. Instead of shooting immediately, he skated back in the slot and then sent the puck past Bobrovsky. Hall now has five goals and three assists in the postseason.

In the waning seconds of regulation, Bobrovsky stopped Marchand on a breakaway to preserve the tie and give the Panthers a chance to win in overtime. Bobrovsky made 44 saves for his first win of the series.

Montgomery said the Bruins spent too much energy chasing the lead during regulation and didn't think they were sharp in the overtime period as a result.

"Our effort was good. But it's really hard to win that fourth game," Montgomery said. "We'll regroup tomorrow and see if we can get the job done on Friday that we didn't get done tonight."