Bruins goaltender Linus Ullmark kneels as the Florida Panthers celebrate a goal Wednesday in Game 2 of the Eastern Conference quarterfinals in Boston. Florida tied the series with a 6-3 win. Charles Krupa/Associated Press

BOSTON — Brandon Montour scored twice and the Florida Panthers had four third-period goals to beat the Presidents’ Trophy-winning Bruins 6-3 on Wednesday night and send Boston to its first loss in 10 games.

The Panthers – the NHL’s top regular-season team last season – tied the best-of-seven series and head home for Games 3 and 4 on Friday and Sunday. There will be a Game 5 back in Boston on Wednesday.

Montour scored 22 seconds into the third period to break a 2-2 tie, Carter Verhaeghe added an insurance goal, then Montour scored again for Florida and Eetu Luostarinen added an empty netter with 2:25 to play to make it 6-2.

Alex Lyon stopped 34 shots, and Sam Bennett and Eric Staal also scored for the Panthers.

Brad Marchand scored a short-handed goal, and Tyler Bertuzzi and Taylor Hall also scored for the Bruins, who won their last eight regular-season games – and 15 of their last 16 – while setting NHL records with 65 wins and 135 points. Linus Ullmark made 24 saves.

Bennett, who missed the opener because of an undisclosed injury, took advantage of a turnover by Bruins defenseman Brandon Carlo in the Boston zone. Matthew Tkachuk kept the puck in and slid it ahead to Bennett, who reached out to corral it and then extended to poke it between Ullmark’s pads.

But the Panthers had an even worse turnover with a man advantage, when Anthony Duclair gave it right to Marchand for the short-handed goal that made it 1-1.

Two minutes later, the Panthers were back in the lead when Staal beat Ullmark, but Boston made it 2-2 just as a power play was expiring, on Dmitry Orlov’s shot that went in off Bertuzzi’s skate.