BOSTON —  The Bruins’ backs officially are against the wall.

The B’s scored three consecutive goals to erase an early two-goal deficit Friday night in Game 4, but the Tampa Bay Lightning held strong, forcing overtime at TD Garden with a third-period score.

That’s where Dan Girardi played the role of hero for Tampa, scoring 3:18 into the extra period to lift the Lightning to a 4-3 win and give them a commanding 3-1 lead in the teams’ second-round Stanley Cup playoff series.

Here’s how this one unfolded:

Tampa Bay set the tone early, scoring two goals within the first 10 minutes of play.

Brayden Point broke the ice just 4:36 into the first period with an incredible individual effort. After a Bruins neutral zone turnover, the Lightning forward weaved through the entire Boston defense and beat Tuukka Rask for his third goal of the playoffs.

Tampa Bay extended its lead on the power play halfway through the period. Defenseman Victor Hedman fed a quick forward Nikita Kucherov, who rocketed a one-timer past Rask from the right point to put the Lightning up 2-0.

David Pastrnak gave the B’s life with a late-period power play goal, though. After Andrei Vasilevskiy stopped a Torey Krug shot from the blue line, Pastrnak batted home the rebound in an impressive display of hand-eye coordination to cut Tampa Bay’s lead to 2-1.

The score was Pastrnak’s sixth of the playoffs and 20th point through 11 postseason games.

The Bruins upped their physicality and aggressiveness during a strong second period.

Boston evened the score early in the frame, cashing in on the power play thanks to a nifty give-and-go between Patrice Bergeron and Krug.

Krug served as the facilitator for Bergeron’s snipe from the right point, which tied the game at 2-2 just 2:04 into the second period.

Moments later, Rask stoned Steven Stamkos on a breakaway attempt to keep things tied.

Boston kept Tampa Bay off the board the entire period while picking up the pace on offense, outshooting the Lightning 14-4. Both squads upped their physical play, as well (11 hits each) — with Brad Marchand again playing the role of instigator.

Marchand transformed into playmaker to set up the Bruins’ third consecutive goal of the night.

The B’s winger broke free down the right on a Lightning power play and whipped a perfect pass to Bergeron, who tipped the puck past Vasilevskiy for his second score of the game, putting Boston up 3-2 with 13:24 to play.

Stamkos finally helped Tampa Bay’s offense break free with 7:04 left in the third period.

The Bruins left Stamkos wide open on the right point and the Lightning star took advantage, ripping a wrist shot past Rask off a J.T. Miller pass to tie the score at 3-3.

Girardi drove the knife into the Bruins’ hearts less than four minutes into overtime, tipping a centering pass from Alex Killorn in front of the net for his second goal of the playoffs.

The series shifts back to Tampa Bay on Sunday for Game 5, where the B’s must win to keep their playoff hopes alive. Puck drop at Amalie Arena is scheduled for 3 p.m. ET.

Thumbnail photo via Bob DeChiara/USA TODAY Sports Images