BOSTON -- Spurred by the return of Marc Savard, Boston had its best offensive output of the season.
Savard made his season debut after missing 23 games because of post-concussion syndrome, while Bruins goalie Tim Thomas made 37 saves to improve to 13-2-1.
"He didn't look like he missed a beat," Bruins coach Claude Julien said. "I liked his game from start to finish and his stamina was great."
"Great to have a guy like him coming back for him personally and for the hockey team," Bruins forward Patrice Bergeron said.
Steven Stamkos, tied for the NHL goals lead with Sidney Crosby with 21, was held without a goal for his fourth straight game. Stamkos and Martin St. Louis had combined for seven goals and seven assists in their last four games against Boston.
"Obviously its embarrassing to get beat like we did tonight and it stings," Lightning goalie Mike Smith said. "We have some work to do. I think it starts with the goaltending out and we have to hold the fort."
Krejci opened the scoring at 10:52 of the first period, rushing up the left wing and wristing a shot past Smith. It was Krejci's first goal since Oct. 30.
Seidenberg made it 2-0 with his first goal of the season. He fired a slap shot from just inside the red line that beat a stunned Smith with 20 seconds remaining in the first period.
Lucic made it 3-0 at 6:48 of the second, before Hedman got Tampa Bay on the board when he converted a nifty feed from Ryan Malone and ended another shutout streak by Thomas at 15:14 of the second. Thomas shut out Philadelphia on Wednesday night and leads the NHL with five.
"When you have momentum, you want to hold onto it because it is easy to lose," Bruins defenseman Zdeno Chara said. "Between last night and tonight, we were able to put together two good games, but once you think you have it, that is when you lose it."
Shawn Thornton made it 4-1 after two, and Krejci, Ryder, Recchi and Wheeler scored in the third.
"Guys are not stupid," Lightning coach Guy Boucher said. "At some point, obviously they're still going, but they're not really going. They're off and it was just a feast for the other team."
Smith was pulled after giving up five goals on 21 shots and replaced by Dan Ellis.
Bruins general manager Peter Chiarelli dismissed reports regarding a trade with Los Angeles for Marco Sturm. ... Boston's Nathan Horton snapped a six-game scoreless streak with a second-period assist. ... The Lightning have allowed 24 goals in the last five games. ... Boston improved to 5-5-2 at home and handed Tampa Bay its first loss of the season against the Northeast Division in seven tries. ... Bergeron played in his 400th NHL game.