The Bruins had the Maple Leafs where they wanted them in Game 5 with a 3-1 series lead. They just showed up late and couldn’t overcome another 4-1 deficit Saturday night.

Two nights later, the Bruins again had the Leafs where they wanted them with a 1-0 lead in Game 6. But mistakes crept in at the worst time and the opportunistic Leafs — playing for a city in healing after a horrific attack that killed nine on Monday — capitalized on their chances for the second straight game en route to a 3-1 win.

Here is what we learned as the series shifts back to Boston for a decisive Game 7 Wednesday night.

Bruins top line continues to dominate puck possession, but still needs to finish

Through two periods, the Bruins were racking up zone time and scoring chances in their attacking end. But, much like the second and third period of Game 5, the lack of finish came back to haunt them.

The top line of Brad Marchand, Patrice Bergeron and David Pastrnak again led the way with 12 shots on Frederik Andersen. Most of those quality chances came in the first two periods. That usually leads to good things. Instead, it led to a frustrating night for the talented trio.

“Bottom line is that we have to bear down and be better,” Bergeron told reporters postgame “[Tonight] we couldn’t find a way. It’s as simple as that.”

Despite their chances, the Bergeron line is scoreless in the three losses against the Leafs. They combined for 23 points in the three victories — 20 alone in the first two games. They’ve set the tone all season long. The only thing that they’re missing is the finish.

Second-period mistakes prove costly

Mitch Marner!

Finds the puck and buries the back hander. 2-1 Leafs. pic.twitter.com/rwzW0AN0BH

— Flintor (@TheFlintor) April 24, 2018

Unlike Game 5, the Bruins came out ready to play. They had numerous chances to beat Andersen — especially after a timely penalty kill with Jake DeBrusk serving a delay of game penalty — through the first 20 minutes but couldn’t find the back of the net.

The Bruins finally got rewarded when Jake DeBrusk fired his third of the postseason past Andersen following a David Krejci faceoff win just 1:02 into the second period.

One trend broke on this night, however, and that was the team scoring first going on to win. A couple of costly Bruins turnovers in their own end led to that stat not coming to fruition.

Just 35 seconds after DeBrusk’s tally, William Nylander banked home a Tuukka Rask rebound for his first of the postseason after the Bruins failed to clear the puck out of their own end. Fellow Leafs youngster Mitch Marner made the B’s pay again at 13:25 when Marchand whiffed on a puck and fired a backhander past Rask for the go-ahead goal.

“They finished their chances from in front of their net and we didn’t,” Bruce Cassidy told NESN’s Jack Edwards and Andy Brickley about the opportunistic Leafs.

Rask up to the task, but Andersen and Leafs D slightly better

When @tuukkarask needs to be clutch, he's clutch. #StanleyCup pic.twitter.com/Mmf9NeDZXf

— NHL (@NHL) April 24, 2018

He’s the most polarizing Bruin, and for sure some people will blame Rask for the Game 6 loss. And yes, he could have positioned himself better on the two goals he allowed — sans Tomas Plekanec’s empty-netter late in the third.

Rask came to play just two days after being pulled for the first time in his postseason career. His bold comments following that Game 5 loss might not have come to fruition, but Rask did all he could to give the Bruins a chance to win, especially with the trio of spectacular saves he made on Nylander, Auston Matthews and Kasperi Kapanen in succession during the final stanza.

One thing is true about Rask, however. The goalie across the sheet is slightly better right now.

Andersen followed up his 42-save effort in Game 5 with a spectacular 32-save outing in Game 6. He didn’t need to make many highlight-reel stops, but Andersen made the timely saves when it mattered. The defense in front of him also chipped in with 23 blocked shots.

Both Rask and Andersen (Game 2) were pulled at one point in the series. Both goalies have bounced back nicely after their early exits. If there’s one area the Bruins and Leafs should feel confident going into Game 7, it’s their goaltending. It might very well come down to that.

They say goaltending is important in the #StanleyCup Playoffs.

Frederik Andersen: Your @GatoradeCanada Performer of the Night. #CoolAsIce pic.twitter.com/6NL25DB7Ys

— Sportsnet (@Sportsnet) April 24, 2018

Should Cassidy shake up the B’s lineup again?

Danton Heinen’s struggles through the first five games led him to the press box on Wednesday night. Tommy Wingels replaced Heinen in the lineup. But instead of notching bottom-six minutes, Bruce Cassidy placed the former Blackhawk on a second line with DeBrusk and David Krejci with Rick Nash, Riley Nash and David Backes starting on line three.

With the Bruins struggling in the third period, Cassidy needed to shake up his lines again. Sean Kuraly moved up to center Rick Nash and Backes on the third line; switching spots with Riley Nash, who logged fourth line minutes with Tim Schaller and Noel Acciari in the third.

Those two lines, along with the Marchand-Bergeron-Pastrnak trio might stay intact at least to start Game 7. But calls for Ryan Donato to return after sitting for four straight games as a healthy scratch are starting to intensify and for good reason.

The Bruins need someone to finish and finally end the Leafs’ hope of a comeback Wednesday night. Donato showed glimpses of potential — and that trademark finish — during the regular season. The former Harvard standout is better served in a top-six role.

Cassidy’s experiment with Wingels didn’t pay off in Game 6. But putting the young Donato in a do-or-die Game 7 would be quite a gutsy decision, but it’s a risk worth taking.