"It was a long time coming, and hopefully it's a sign of good things to come," Kelly said. "It was a lucky bounce, but I'll take it."
Paille added a short-handed, empty-net goal with 1:37 left when the Panthers pulled Markstrom to give them a 6-on-4 skating advantage.
The Panthers have scored on only one of their past 24 power plays, including the four-minute advantage when Lucic went off for cross checking and roughing.
"Those are momentum changers in the game," Panthers coach Kevin Dineen said. "There's different areas in the game that change momentum, and that's definitely one of them."
Markstrom played well in his second game since being called up from San Antonio of the AHL on Wednesday. The three goals against him were all difficult to defend, especially the one scored by Chara.
"What can I say? It's a good hockey play and a good shot," Markstrom said. "I didn't think he was going to score, but he did. That's a good goal."
NOTES: Bruins RW Nathan Horton has never scored in eight games against his original NHL team. Horton played for the Panthers from 2003-10. ... The Panthers' home-losing streak is their longest since an 0-4-1 stretch from Feb. 16-March 6, 2011. ... Panthers F Alex Kovalev turned 40. He is among eight active 40-plus players in the NHL.