Rafael Harvey-Pinard and Kale Clague each scored his first NHL goal for the Canadiens (7-21-4), who have lost six straight. Montembeault made 32 saves.
"For sure it's frustrating; on top of it, this is the second time they've done this to us, they did it to us at the Bell Centre last time," Monteambeault said. "But it's mostly frustrating because it's happened this year where we were down in the game by a little bit and we came out for the third period with no energy.
"But this time we did the opposite; we played an excellent third period. That's why it hurts even more. We wanted to go get that win. But unfortunately they tied it with 19 seconds left and it really hurt us."
Lukas Vejdemo gave the Canadiens 1-0 lead at 10:45 of the first period when he gathered a loose puck in front of the crease and scored in the open net.
Point, who missed 14 games with an upper-body injury, tied it 1-1 at 11:38 when he made a move on a 2-on-1 breakout and chipped in a shot from the slot. He gave the Lightning a 2-1 lead at 14:10 with a tip in off a pass from Alex Killorn.
"The game doesn't change, but some of the timing was a little off," Point said. "Little bit off in the early parts of the game, but I kind of felt better as the game went on."