Surprise, surprise. The Toronto Maple Leafs can play a patient game.

Maybe all these hard lessons from the previous 17 playoff games in the last three springs finally have sunk in for Auston Matthews and Co.

In their 18th post-season outing together, the Maple Leafs waited and waited for their chances to materialize in a tight-checking Game 5. Finally, in the third period, they were able to convert on a couple of opportunities for a brilliant 2-1 victory to take a 3-2 series lead in Boston against the Bruins on Friday.

Toronto has an opportunity to win its first series since 2004 when Boston visits Scotiabank Arena for a matinee affair on Easter Sunday.

The opportunity to clinch came about because a passing lane opened up midway through the final period.

Toronto defenceman Jake Muzzin, who welcomed a baby girl into the world on Thursday, faked a shot. He then took a stride forward but spotted Matthews to his right. Muzzin hit his teammate with a pinpoint pass for a 28-foot one-time shot that beat Bruins goalie Tuukka Rask with eight minutes and 27 seconds remaining.

Yesterday, Jake Muzzin became a dad.<br><br>Today, Jake Muzzin assisted on a huge Leafs goal to break the 0-0 deadlock.<br><br>Not a bad 24 hours, eh Pops? <a href="https://t.co/DjtRC3bR6y">pic.twitter.com/DjtRC3bR6y</a> —@hockeynight

There was a strong case for goaltender interference on Maple Leafs left wing Zach Hyman. The Toronto forward went to cross-check Bruins defenceman Charlie McAvoy in the back. Hyman lost his balance and then bumped into Rask, prohibiting the Bruins goalie from pushing across on the Matthews shot. But after a lengthy review, the league ruled it a good goal.

The NHL stated its decision was made in accordance to Rule 78.7, that states in part, "If a review is not conclusive and/or there is any doubt whatsoever as to whether the call on the ice was correct, the original call on the ice will be confirmed."

It was a surprising decision to objective observers. Even Matthews didn't appear confident on the bench as the video review trudged on. After glancing to watch the replay on the scoreboard, he put his head down to wait for the decision.

WATCH | Highlights from Toronto's win:

The Maple Leafs beat the Bruins 2-1 in Game 5 to take a 3-2 series lead in their 1st round series. Game 6 is set for Sunday at Scotiabank Arena. 2:13

"I was just praying they were going to call it a goal," Matthews said. "I haven't had the best of luck on those types of goals in my career.

"You always hope for the best. I didn't get a good look at it. It was fortunate they called it a good goal. It was nice to break through for one."

Hyman didn't bother to take in the replay.

"I didn't watch it," he said. "I didn't want to watch it."

A cool and calm Rask took the high road afterward.

"I don't know. I felt there was contact there," Rask said. "So I went after the ref to let him know there was contact.

"I trust they got it right."

Boston Bruins' Tuukka Rask cannot stop a goal by Toronto Maple Leafs' Auston Matthews. (Michael Dwyer/The Associated Press)

Bruins coach Bruce Cassidy felt the league didn't get it right. But he also kept his cool in his post-game remarks.

"From my viewpoint, it certainly looked like interference," Cassidy said. "It's a 1-0 game with eight minutes left and we had time to get back in the game."

Instead, it was the Maple Leafs who forged ahead. Matthews made a dandy short breakout pass to teammate Morgan Rielly, whose rush led to a two-goal lead on a goal from Kasperi Kapanen.

WATCH | A Tale of Two Goalie Interference Calls:

Both the Toronto Maple Leafs and Calgary Flames had a goal reviewed due to goalie interference on Friday, but with two very different game results. 1:07

Boston's David Krejci made it close with a goal 44 seconds remaining. But the Maple Leafs hung on.

Too many times in the past this group has exhibited a lack of grit, lapses for extended stretches, head-scratching miscues in their own end and reliance on goalie Frederik Andersen to save the day.

Andersen was brilliant again. But his teammates played well in front of him. They were solid in moving the puck out of their own end.

Matthews particularly was strong. He now has four goals in five games in this series after scoring just once in seven games against Boston a year ago.

His play, Andersen's play, the Maple Leafs patience resulted in a deserving win, whether or not that was goaltender interference.