The Rangers beat Montreal 3-2 on an overtime winner by Martin St. Louis over the shoulder of Habs' goalie Dustin Tokarski.
It was the 10th game-winning playoff goal of St. Louis's career, and his fourth in overtime.
The goal was payback for a couple of earlier saves by the rookie Tokarski on the veteran, including a brilliant glove-hand stop on a St. Louis breakaway.
Tokarski was again on his own against the Rangers much of the night, as his team struggled to get organized.
The Habs had their share of chances, including eight power play opportunities in regulation time, but only managed to cash in once. They got another opportunity in overtime, but their power play faltered once again.
The Habs came close to evening the series when Alex Galchnyuk hit the Rangers' cross bar with just over three minutes to play in the third period. Rangers' goalie Henrik Lundqvist got just enough of the puck to deflect it.
The end came when the Habs missed two chances to clear the puck out of their zone and St. Louis buried a shot he has practised hundreds of times in practice.
The Habs have one more chance to work out their power play woes in Game 5 at the Bell Centre tomorrow.
The CBC Montreal Sports team has you covered for the Montreal Canadiens' 2014 Stanley Cup playoff run. Andie Bennett and Doug Gelevan are with Habs from the first round all the way to the victory parade.
Check out cbc.ca/montreal every morning for highlights, interviews from the locker room and the latest reports from Doug and Andie in Montreal and on the road.