The Sabres responded by scoring twice in the period off the sticks of Ristolainen and fellow defenseman Marco Scandella, setting the tone for what ended as a 3-2 victory.
Buffalo shut down Los Angeles long enough for Victor Olofsson to deposit an empty-net goal with 1:33 remaining, extending his point streak to six games. Dustin Brown scored the Kings' second goal with just 37.7 left on the clock.
It was a resilient effort from the Sabres following their 6-1 loss in Philadelphia on Thursday. Jack Eichel was back in the lineup after missing that game with an upper-body injury and looked like himself, tallying six shot attempts and an assist in a team-high 22:11.
As important as the prescence of their captain was, so was the Sabres' ability to stick with their game plan in the face of adversity. None of the players who spoke after the game were happy with their first period, which ended scoreless but with a 10-6 shot advantage in favor of the Kings.
When Kempe opened the scoring for Los Angeles to start the second, Buffalo responded with its best hockey.
"You could just feel everybody raise the game after the goal against," Sabres coach Ralph Krueger said. "It really launched a strong stretch where I thought we could've had even more of a lead than we had."
"We were just playing with more confidence, tracking harder, getting pucks deep, and just feeling good about our game," added Scandella.
Kempe's goal wasn't the only moment of adversity the Sabres faced in the period, either. Sam Reinhart had what would have been the go-ahead goal waved off because of an early whistle, a call that could have shifted momentum in either direction. Scandella's goal came less than a minute later, a slap shot from the point fed by Reinhart.
"It shows resiliency," Scandella said. "We didn't let ourselves go down after that. We just kept pushing, and I felt like we had a really good second period."
Linus Ullmark robbed Anze Kopitar just before the horn sounded to end the second period, as big as any of the 25 saves he made in the victory. The Sabres entered the contest 13-0-0 when leading after two periods, a record they improved upon with their third-period effort.
"I think more than anything, it's learning to deal with those situations, period," Krueger said. "Every team in this league has the skill and the danger to press when they're down in the third and to go all-in. It's always very threatening. I'm just proud of the guys understanding what it takes and the work and the inside positioning.
"The management of the puck, especially, is something that we're getting better at all the time. We still have a ways to go. There were a couple of breakdowns we didn't like so much in the third, but you're always going to have them when a team pushes with that strength. But it is a mindset. It's playing for the team, sacrificing and doing what the team needs. That's how you get those finishes like we did today."