TORONTO -- There was never going to be a complete shutdown of the Toronto Maple Leafs.

The Boston Bruins knew it. The Maple Leafs knew it. And so it was no surprise that Toronto got back into the Eastern Conference First Round with a 4-2 win in Game 3 on Monday, when the Bruins showed a few defensive vulnerabilities.

Now that it has happened, Boston, which leads the best-of-7 series 2-1, has turned its focus to those vulnerabilities entering Game 4 here on Thursday (7 p.m. ET; NBCSN, CBC, TVAS, NESN), to finding ways to balance what the Maple Leafs want to do with what the Bruins want to do.

[RELATED: Complete Bruins vs. Maple Leafs series coverage]

That starts with countering sequences in which the Maple Leafs take advantage of their speed and quickness, sequences like the one that yielded their second goal in Game 3.

After a Bruins shot, Toronto defenseman Morgan Rielly collected the puck, went behind his own net and sent it up the right boards and through Boston defenseman Kevan Miller, who was pinching. The puck found Maple Leafs forward Mitchell Marner, who had a clear path on the right side to the Bruins net.

Maple Leafs forward Patrick Marleau, who had gotten in front of the Bruins defense, was there to finish a pass from Marner for a goal that gave Toronto a 2-1 lead at 3:49 of the second period, 43 seconds after Boston had tied the game.

Video: BOS@TOR, Gm3: Marleau finishes Marner's great pass

It was the opposite result from Game 2, when Miller pinched and ended up scoring the third goal for the Bruins in their 7-3 win. On that first-period goal, Miller came off the bench and slid down the left side, making him available to take a pass from forward David Pastrnak. After some spins around Maple Leafs forward Tomas Plekanec, Miller banked the puck off the skate of Toronto defenseman Nikita Zaitsev and in.

"I go back to Game 2, Kevan Miller is active, we score a goal off it," Bruins coach Bruce Cassidy said. "If that doesn't bounce in, they get possession, they recover, loose puck retrieval in their end, off their wingers go. So, we need a forward to cover for Kevan down there, or we have to replace [him] on time. That's the trade-off."

It has worked for the Bruins sometimes. They have caught the Maple Leafs, as Cassidy put it, "I don't want to use the word 'cheating,' but leaning the other way."

But it doesn't always work. Sometimes, as in the case of the Marleau goal, it costs them.

Not that the Maple Leafs, who have the speed to often use those stretch passes to their advantage, have seen many such opportunities in the series. They were contained, mostly, when Boston outscored them 12-4 in winning Games 1 and 2 at TD Garden.

"I think anytime you can transition from defense to offense fast, you can have a chance for success for sure," Toronto coach Mike Babcock said. "In saying that, the Bruins have done a pretty good job against us and we haven't had the amount of success we've normally had.

Video: Discussing the Bruins performance in Game 3

"The other thing is, the harder you come back that quickly, the better chance you have of having success in that transition. We have to do a better job in that area if we are going to continue to have success."

Which means each team is vowing to do better.

"I think [it's] just making sure our neutral zone is tight, our forwards are guarding that red line pretty well and then our defense can have a tight gap," Bruins defenseman Torey Krug said. "It doesn't allow them to make many plays. It's more, chipping pucks in, and then go back and get some clean breakouts."

But that doesn't mean that Krug, or any of the Boston defensemen, are going to stop pinching. The Bruins believe in being aggressive, seeing how that can work out in their favor, as it did on that Miller goal. They just need to be smart about doing it.

"We have to balance O-zone play, risk-reward, vs. their stretch, blow-the-zone type of mentality," Cassidy said. "And that's what it comes down to."