Mason Lohrei scored once and added an assist and the Boston Bruins used a three-goal second period to claim a 5-1 victory over the Florida Panthers in Sunrise, Fla., on Monday in the opener of an Eastern Conference semifinal series.

Morgan Geekie, Brandon Carlo, Justin Brazeau and Jake DeBrusk also scored for the Bruins, who reached the second round of the Stanley Cup playoffs thanks to their Game 7 win over the Toronto Maple Leafs on Saturday.

Boston goaltender Jeremy Swayman made 38 saves, and Pavel Zacha collected two assists. Swayman has surrendered two goals or fewer in all seven games he has played in the postseason.

"Absolutely incredible," Carlo said on ESPN of Swayman. "From a defenseman like myself, I love the defensive side of the game, but having a guy like that behind you speaks volumes."

Boston coach Jim Montgomery added, "I think our confidence has gone to another level after pushing through the first round. And that confidence makes you believe that you can (win). It's a great place to be mentally."

Matthew Tkachuk scored for the Panthers, who racked up 110 points in the regular season and finished atop the Atlantic Divisions standings, one point ahead of the Bruins. Florida needed only five games to beat the Tampa Bay Lightning in the opening round of the playoffs.

Panthers goalie Sergei Bobrovsky stopped 24 shots.

"We weren't great tonight," Florida coach Paul Maurice said. "I don't know if the game was exactly like the score, but it doesn't matter. They played well, they looked like they were in a bit of a rhythm. I thought they played a very patient game, so good for them and not so good for us."

Game 2 of the best-of-seven series will be played Wednesday in Sunrise.

The Bruins have won all five meetings between the teams in 2023-24 (regular season and postseason) after Florida knocked them out of last year's playoffs in the first round.

Only 67 seconds after Boston fell behind 1-0, Geekie tied the clash with his third goal of the playoffs at 12:52 of the second period. A Florida turnover resulted in a scramble at the net, and Geekie pounced on the loose puck before sending it past Bobrovsky.

Lohrei's first career playoff marker came at 16:17 of the middle frame, and it served as the go-ahead goal.

Carlo, whose wife delivered a baby boy earlier Monday, made it 3-1 with 21 seconds remaining in the second. Carlo joined a rush and found the mark from the right circle to net his second goal of the playoffs.

"It's been wild, for sure, but so blessed," Carlo said postgame on ESPN. "This group, from Game 7 (against Toronto) to here, I'm so fortunate to play with these guys. I'm so proud of my wife, she did amazing -- we had the baby about 3 o'clock. Pretty busy night and I wasn't sure I was going to make it, but so happy I did."

Brazeau added his first career playoff tally 7:13 into the third period by converting a backhanded deke on a breakaway, and DeBrusk added an empty-net goal to round out the scoring.

After a goalless opening period, Tkachuk broke through at 11:45 of the middle frame. Taking advantage of a Boston turnover, Tkachuk gained the puck in the high slot and used a screen to record his fourth goal of the postseason.

--Field Level Media