TORONTO—The Bruins were facing a situation in which they needed their best players to be the their best players.

One of them stepped up in a big way.

Brad Marchand scored his first goal of the series in the biggest moment so far. Just seconds after the Leafs had tied the game, Marchand sniped a shortside shot over Ilya Samsonov’s glove to make it 3-2 They held up for the game-winner in the 4-2 win, leading to a 2-1 series lead over the Toronto Maple Leafs at Scotiabank Arena.

With the B’s trying to kill a 6-on-5 situation, John Tavares took a holding penalty with 1:04 remaining.

When the Leafs took control of the puck, they pulled Samsonov again, but Machand put the nail in the coffin with empty-netter with 35.8 left.

Jeremy Swayman was pretty good, too, turning away 28 of 30 shots for his fifth win against the Leafs this season.

The scoreless first period was an entertaining one nonetheless, with both teams having a couple of decent chances in the hard-hitting opening 20 minutes (the B’s held a 32-28 hit edge, according to the local stat crew).

The B’s got the first break of the night when Simon Benoit shot the puck into the stands on the first shift of the game, but the B’s could not capitalize on the advantage.

Shortly after the B’s power play was up, rookie Mason Lohrei, in his first Stanley Cup playoff game, got tagged with a crosschecking penalty in front of the net on Tyler Bertuzzi. The B’s killed that off well and had the best chance of the two minutes, a clean breakaway for Pavel Zacha that Ilya Samsonov just got a piece, the puck dribbling just wide.

The B’s had a great 5-on-5 chance when Charlie McAvoy took the puck behind the net and his wraparound attempt went out to David Pastrnak on the right side. Samsonov was out of the net, but Joel Edmundson stepped in for a goal-saving block.

The Leafs best chance came when Parker Wotherspoon, also playing his first Cup playoff game, was double-teamed behind the net by Bertuzzi and Max Domi, who stepped out from behind the net for an open shot, but Jeremy Swayman gave him little at which to shoot and gobbled it up.

While the B’s had the hit advantage on the stat sheet, the Leafs delivered a couple of thunderous checks late in the period that had the crowd roaring. First Benoit blasted Pastrnak just inside he Leafs blue line, then Ryan Reaves crushed Zacha with a clean check in the neutral zone.

Auston Matthews had a couple of good opportunities early in the second period. The first one came when Lohrei stepped up in the neutral zone, couldn’t get the puck and gave the Leafs a 2-on-1. Matthews kept it and pinged the far post.

His second chance came on a power play with Pastrnak in the box for hooking on a back-check. Swayman stoned him on a wide-open shot from the right circle.

But the Leafs finally broke the ice at 13:10. After Pastrnak had a shot blocked, it produced a big rebound and a 3-on-2 for the Leafs. Matthew Knies finished off the play, tapping home Mitch Marner’s pretty pass for the 1-0 lead.

The B’s hadn’’t been getting many chances in the second, but shortly after the goal, James van Riemsdyk had a breakaway. Making his first appearance in the series, van Riemsdyk tried to tuck it between Samsonov’s pads but the netminder closed them in time.

Then the refs put the whistles away, to the B’s benefit. First, McAvoy slammed Matthews to the ice behind the B’s net, no call.

Then Brad Marchand and Bertuzzi were battling each other in the middle of the ice, a gloves-on scrap that that had the attention of the entire crowd. Samsonov must have had one eye on it, too, because as the tiff was going on the crowd was screaming for the refs to something, anything, Trent Frederic beat the netminder with a long-range shot from the left wing with 2:23 remaining in the period.

The locals were not happy.

Shortly after that, with the crowd still in an uproar, the refs called a makeup rouging penalty on McAvoy. But even then, the Leafs couldn’t take advantage as Bertuzzi wiped it out with a high-stick on Charlie Coyle.

That would give the B’s a power play to start the second and the B’s took their first lead of the game at 1:07. Marchand came out of a pileup on the riihgt boards with the puck and got a shot on net that Samsonov stopped. But with three Leafs still over at the boards, Jake DeBrusk had time to gather the rebound and score his third goal of the series.

The Leafs got a second cheapo call when Lohrei was whistled for hooking Matthews on what looked like a clean check. On the kill, Swayman made two huge saves on Bertuzzi right off the at the bat the B’s killed it off.

But they could not hold the lead as the Leafs tied it on pinball with 8:35 remaining in the thirdwhen Morgan Rielly’s shot went off Bertuzzi’s skate, then Hampus Lindholm’s shin and in.

Just 18 seconds later, the B’s captain gave his team the lead again, sniping a shot fomr the right circlle for the 3-2 lead.