Raddysh finished a pass from Kucherov with a one-timer from between the circles at 15:50 to make it 5-3, and Nick Paul scored just 23 seconds later at 16:13 on a tap-in from a feed from Guentzel to cut the deficit to 5-4.
"We know they are a great team over there and to get out to the lead we did, when we did, being in control of the game and just hand it right back to them, especially in our division and what we are playing for right now, just adds to the volume of everything," Geekie said. "This one stings for sure."
Kucherov then scored on a one-timer from the right circle to tie the game 5-5 at 11:50 of the third period.
"It was very special, honestly," Lightning forward Yanni Gourde said. "Just the way this game, how it had happened. Being down 3-1 and getting outshot 20-8 in the first period, it was not at all the way we wanted to start a game. But in the 2nd period, we changed our identity. We went back to what we do best and simple hard hockey, and we found a way."
The Bruins took 11 penalties and allowed three power-play goals on eight chances.
"The way the game went, we just didn't have our composure I would say," Bruins coach Marco Sturm said. "They were just better than us after the whistles. I don't think they were better than us today hockeywise, I thought they were better than us after the whistles."