Pavel Dorofeyev scored twice, and Schmid made 23 saves for Vegas (25-14-13), which lost 7-1 at the Ottawa Senators on Sunday and is 1-3-1 in its past five games.
“We were down going into the third [period] and we've done a good job this year getting back in the game," Cassidy said. "We're never out of it, so that's a positive. I thought it was a good game. We played with pace. Offensively, I thought we generated some good looks. I thought both goaltenders had good nights, so there was a lot to like.
"The second period, the game got away from us a bit and that's a problem for us lately. We have just not been able to reclaim our game to sort of get back in it. And one turns into two, lately it's been two turning into three, so at least there was that. We kept it within a goal so it's there for us, and we end up getting the tying goal. So those are the positives."
Dorofeyev scored his second of the game at 16:52 of the third period to tie it 2-2 with a deflection past Dobes’ glove on Ben Hutton’s shot from the left point.
“Obviously you don’t want to give up one late, but I like the way we responded, and we were able to get that extra point in overtime, which is huge,” Canadiens defenseman Noah Dobson.
Dorofeyev gave Vegas a 1-0 lead with an unassisted goal at 8:38 of the first period. He carried the puck along the left side on a 2-on-1 with Braeden Bowman and scored glove side on Dobes with a wrist shot from the left face-off dot.