TORONTO — Even without Auston Matthews, the Bruins still had problems with the Maple Leafs during a pivotal Original Six matchup.

Those problems were exacerbated by another controversial goaltender interference challenge, and one of their star players leaving the arena in a walking boot.

Despite leading twice, the Black and Gold didn’t have many answers against a well-tuned Leafs bunch Saturday night at the Air Canada Centre. Here is what we learned as the B’s relinquish their hold on second place in the Atlantic Division following their 4-3 loss to Toronto.

Another outcome decided by goaltender interference

Ron and done. #TMLtalk pic.twitter.com/S1ErEsSLlf

— Toronto Maple Leafs (@MapleLeafs) February 25, 2018

Another night where everyone in the hockey world asks: what constitutes as goaltender interference? Until there’s a clear guideline as to such, the grey area involving goaltender interference reviews won’t be going away anytime soon.

With just 1:23 left in regulation, Ron Hainsey fired a slap shot past a distracted Tuukka Rask. The Bruins netminder immediately questioned the goal with the officials after Zach Hyman shoved Charlie McAvoy to cause the distraction.

“I’m sure I would’ve stopped the puck if I was there,” Rask said of the incident. “I couldn’t get there on time because someone interfered with me.”

After a lengthy review following Bruce Cassidy’s challenge, the call on the ice stood, and the Bruins were left scratching their heads over the latest conundrum surrounding goaltender interference.

“I don’t know what goaltender interference is,” a frustrated McAvoy said postgame, “and I know I’m not the only one. We’ve seen it work in our favor and we’ve seen it work against us now and there really isn’t just a fine line.”

“I think it’s frustrating when they start deciding games,” Rask said after his 32-save effort. “You battle 59 minutes…and then a [expletive] goal cost us the game. Luckily it hasn’t happened to us too often.”

Instead of forcing overtime, the Bruins had to settle for a tough regulation loss and relinquish their second place standing — a spot they’ve held since December — to their rivals from up north thanks in large part to another frustrating night involving video replay.

Things get away from Bruins in the second

Though Brandon Carlo’s defensive breakdowns led directly to the Leafs two first period tallies from Mitch Marner and Nazem Kadri, the Bruins still matched the Leafs chance for chance in the opening 20 thanks to Brad Marchand’s 23rd and 24th of the season. Things got away from the Black and Gold in the middle stanza, however, as they spent a significant amount of time in the defending end.

Jake DeBrusk kicked the second period off with a tip-in on a great feed by Ryan Spooner. That was the only highlight of their middle 20 as they were hemmed deep in their zone afterward and were outshot 17-1 since DeBrusk’s 12th of the season at 1:55.

The B’s were fortunate to head into the locker room tied 3-3 after Nazem Kadri added his second power-play tally at 19:04.

“What happened was they were a lot better than us,” Cassidy said. “We came out tied 1-1 in the second, but they were clearly the better team. I thought that our gaps from our D weren’t good enough to kill some plays so we could get some transition going whether its breakout or neutral zone — and part of that is because you don’t get pucks behind their D — and they have it in the neutral zone ready to go. So it was a combination of both and then you start killing penalties and then it adds up and gives them momentum.”

Bergeron leaves in a walking boot

Patrice Bergeron didn’t miss a shift in his 19:15 of ice time, but The Hub of Hockey is on edge after he left the Air Canada Centre in a walking boot. The Hart Trophy candidate was engaged in a puck battle in front of the benches during the first period that apparently led to the walking boot.

Cassidy said he expects the same 12 forwards to be in the lineup when the B’s face the Sabres to conclude their five-game road trip on Sunday. Those comments were made prior to Bergeron leaving the arena. Bergeron’s status will likely be confirmed when Cassidy meets with the media prior to the 5 p.m. puck drop in Buffalo.