Lundqvist made two of his best saves in the third period on Kyle Okposo and Sam Reinhart with the Rangers on the penalty kill that preserved the one-goal advantage.
But Buffalo would break through late in the period on a goal by Cody Franson, who fired a low wrist shot from the slot that eluded Lundqvist to send the game to overtime.
Lundqvist would follow those saves up with another stop on Okposo, this time in overtime.
"The pass wasn't that hard so the key wasn't to overplay the situation and kind of follow the puck and not push too hard," Lundqvist said. "Then the shot came. He was going closer to my body than I expected. I thought he would go close to the puck. It was just a quick reaction but I had good patience there and a little luck."
New York had a chance to win it midway through the overtime period when Michael Grabner broke in alone but was slashed on the shot, leading to a power play. And while the Rangers failed to convert, Kreider's winner came just moments later.
Thursday's victory was the team's 14th of the season in 19 opportunities following a loss.
"I think that's a good thing," Kreider said. "Obviously you don't want to stack losses. I think it speaks to our resiliency. You never want to go on a slide. It's definitely a positive."
The other positive, of course, was the play of No. 30.
Lundqvist said he feels his game is not far off, but the key for him at this point is to still give his team a chance to win even when he's not at his best.
"I battled. I battled hard. My game is right there," said Lundqvist. "It's about consistency. I put together four or five real strong ones and then I take a step back and have a C game. I need to have more B games. A games, I feel like I have A games. It's just when I have a drop, it needs to be a drop to a B and not a C, because then we're still going to have a chance to win."
