Simon Gagne scored to snap a tie nearly seven minutes into the third period as the Tampa Bay Lightning rallied from a three-goal deficit to post a 5-3 home triumph over the Boston Bruins on Saturday in Game 4 of the Eastern Conference finals.

Teddy Purcell netted a pair of goals and Sean Bergenheim added his NHL-leading ninth of the postseason for fifth-seeded Tampa Bay, which knotted the series at two games apiece. The Lightning will look to regain the advantage when the teams reconvene in Boston for Game 5 of Monday.

With the game tied at 3-3, Boston's Milan Lucic forced an ill-advised pass in the neutral zone. Ryan Malone intercepted the puck and skated into the right faceoff circle before feeding a trailing Gagne, who wristed a shot past Vezina Trophy finalist Tim Thomas for his 36th career playoff goal at 6:54 of the third period.

Hart Trophy finalist Martin St. Louis preserved the victory with 37 seconds remaining by scoring an empty-net goal.

After Patrice Bergeron netted his second goal of the game to give Boston a 3-0 lead and chase Dwayne Roloson, Mike Smith relieved the 41-year-old netminder and stopped all 21 shots he faced to remain perfect in two appearances in this series. Smith stopped all eight shots in Tuesday's 6-5 loss in Game 2.

The goaltender switch on Saturday ignited the Lightning, who scored three times in a span of 3:58 into the second period to level the contest at 3-3.

After accepting a feed in the slot, Purcell deked defenseman Adam McQuaid before unleashing a backhand which beat Thomas inside the far post. The goal was the first allowed by the All-Star in over 93 minutes of playoff hockey.

Purcell then trimmed the deficit to one with a wrist shot which beat Thomas over his glove and under the crossbar.

Bergenheim then outworked Bruins defenseman Tomas Kaberle from behind the net, skated out in front and wired a shot between Thomas' pads to level the contest at 3-3. The offensive explosion is a welcome sight from Bergenheim, who scored just 14 times in 80 regular-season games.

Bergeron took advantage of a defensive miscue for Lightning blue-liner Victor Hedman to open the scoring at 11:47 of the first period.

Michael Ryder doubled the advantage nearly five minutes later after his attempted feed to Chris Kelly was denied by defenseman Mike Lundin. The puck, however, skidded on goal and past an overcompensating Roloson and into the net.

Bergeron netted his second of the contest and team-leading 14th point just 84 seconds later after taking advantage of Steven Stamkos' turnover in the neutral zone. Bergeron then skated in and wristed a shot from the left faceoff circle which beat Roloson between the pads.

Thomas finished with 32 saves.