The tally also ended a lengthy goal-less streak for Greer, who potted three goals over the season's first four games before going 22 games without one, the last coming on Oct. 18 against Ottawa.
"It was definitely a great feeling. I think I was due," said Greer. "I think you put a little pressure on yourself when you get to a few games where you don't score, or you don't get on the scoresheet. You know you're playing kind of the right way, but you aren't getting rewarded and you aren't getting as many looks as you want to.
"I think getting that shot off and scoring just kind of released a lot of pressure off my back, but credit to my linemates. I think we had a great night together. We brought the energy and played well in both zones."
Greer was also in the middle of a large scrum at the end of the second period, which had both teams lingering at center ice before finally retreating to their dressing rooms. The winger was not pleased with Toronto's Michael Bunting for a hit on Patrice Bergeron and let him know it, which led to Wayne Simmonds stepping in for some further pleasantries.
Greer and Simmonds were both issued 10-minute misconducts.
"I mean, I think if you're going to come after Bergy like that, you have to respond," said Greer. "I didn't do much, I was just going to go and tell him that, 'Hey, if you're going to do that, you have to pick your head up.'
"We got in the penalty box, and I told Simmonds, 'You would've done the same thing! And he was like, 'Yeah, I would.' So, it's just how it goes."
Montgomery was pleased with the way his players stuck together during the altercation.
"I think A.J. loves being a Bruin and I think he knew what he was doing tonight," said Montgomery. "I thought we played with the right amount of emotion, and we didn't get emotional, and that's hard not to do in a game like tonight. Like the scrum at the end of the second - there was some emotion going on, and I just liked how we all stuck together out there.
"They did too. There's players on their team that certain guys on our team don't like, and I'm sure it's the same way [for them]. That's what makes a rivalry, and that's why it was such a heated, good hockey game."