Hockey is a funny game.

On Tuesday, the Bruins did everything right except put the puck in the net in a 2-0 loss to the Vancouver Canucks. On Wednesday on Long Island, the B’s had all sorts of puck management issues, but they came away with a 6-3 win over the New York Islanders.

The B’s coughed up a two-goal lead and then another one-goal lead, but Pavel Zacha scored two third-period goals to lift he B’s to victory. Brad Marchand also scored a paired of goals while Morgan Geekie and Nikita Zadorov had the others.

The B’s are now 3-1 under coach Joe Sacco. While the first two wins came on team defense, the dam finally broke offensively on Wednesday, as Charlie McAvoy had wished and hoped it would after the frustrating loss to the Canucks.

The Bruins entered the game with just one 5-on-5 goal in their previous 14 periods of hockey. But the player who scored that one even-strength goal, Marchand, scored two of them in the first 6:31 in Wednesday’s game.

The first one came just 57 seconds into the game and it was as simple as it could get. Elias Lindholm won a faceoff in the left circle to Marchand in the slot, where he snapped it over Ilya Sorokin’s blocker.

That put some jump in the B’s skates and Marchand made it 2-0 at 6:31 off the rush. Skating through the middle of the zone, Lindholm tried to filter a pass down to Justin Brazeau in the low slot. Brazeau couldn’t control the puck for a scoring chance of his own, but he was able to deftly drop it back for Marchand, who buried is eighth of the season.

At that point, Islander coach Patrick Roy called his timeout to stop the bleeding. It was an effective tourniquet.

The Islanders forced the B’s into some turnovers that, since the coaching change, had been relatively rare. They cut the Bruin lead in half on a giveaway.

Parker Wotherspoon was on his off side and tried to backhand the puck up to Trent Frederic on the right side but the gap was too big. Brock Nelson stepped in to steal the puck and got it to Maxim Tsyplakov, who’d slipped in under the B’s layers. He didn’t get all of his backhander, but it found it’s way between Joonas Korpisalo’s pads to make it 2-1 at 12:50.

The second period did not have feature as many scoring chances in the early going as the first but all it took was a bouncing puck for the Islanders to tie it up at 8:52.

Mason Lohrei looked to be in good shape to corral a puck at his blue line, but it bounced over his stick and gave Nelson a clean break-in. Korpisalo left too much of the shortside and Nelson took it, zipping the equalizer past the netminder.

Sacco had tried loading a line with Marchand, Lindholm and David Pastrnak early in the second but, when he went back with the original lines, the B’s reclaimed the lead.

Zacha knocked down an Islander clear attempt on the right wing and immediately got it low to Pastrnak, who in turn dished it back to Zacha. Zacha had a promising scoring chance but he elected to to move it to Morgan Geekie, who had an open net for the go-ahead goal at 11:59, just his second of the year.

The B’s should have been into the second intermission with the one-goal lead, but the B’s gave the Isles a backbreaking goal with 7.2 seconds left in the second.

After Lorhei’s turnover, he was replaced on the top pairing with Nikita Zadorov. With the clock winding down, Zadorov skated the puck on the left side as Bo Horvat applied what looked like token pressure. Instead of moving the puck up the ice, Zadorov opted to throw it back in the middle of the ice for Charlie McAvoy. Horvat deflected it and everything went haywire

Zadorov recovered in time to thwart Nelson’s initial chance but McAvoy fanned on his flip-out attempt and the Islanders kept it in. Eventually Nelson ripped his second of the game from the left circle and it was 3-3 headed into the third.

The Islanders controlled the play early in the third period but the B’s got yet another go-ahead goal at 10:48.

Sorokin misplayed a clear-in and Marchand got in on the forecheck to create some havoc. Pastrnak fed Andrew Peeke out high and the defenseman wasted no time in shooting it. Parked in front,, Zacha deflected it past Sorokin.

Zacha gave the B’s their two-goal lead back at 13:22. Pastrnak stole the puck behind the Islander net and he delivered a deflected pass out to Zacha, who beat Sorokin with a backhander, his sixth of the year.

As he’s wont to do, Roy got aggressive and pulled his goalie with five minutes left and, on the 6-on-5, Zadorov took the first penalty of the game with 4:10 left.

The B’s did a great job of killing it off and Zadorov stepped out of the box in time to collect the clear out and tuck home the empty-netter for is first as a Bruin.