Drew O'Connor made it 2-0 at 16:24 of the second period with his first goal of the season. He carried a pass from Lars Eller to above the right face-off circle and scored with a wrist shot that clipped Luukkonen’s blocker.
“They came out, they played hard and they really stuck to their game plan,” Buffalo captain Kyle Okposo said. “In saying that, I still think we did a lot of really good things tonight, too. I don't think the score was quite indicative of how the game went. We could've easily had a few goals in the first two periods.”
Karlsson extended the lead to 3-0 when his shot deflected in off the stick of Buffalo defenseman Erik Johnson on a power play 27 seconds into the third.
"They want to trade chances. We just can't let that happen,” Sabres defenseman Rasmus Dahlin said. “We've got to play it simple sometimes, especially on a back-to-back. It was a bouncy game.”
Karlsson then scored an empty-net goal for the 4-0 final with 1:49 remaining. He has nine points (three goals, six assists) on a five-game point streak.
“As of late, it feels like it’s starting to come together a little bit more,” Karlsson said. "Things are falling into place a little bit easier and we’re starting to get the results to go with that. We've won a couple games where we haven’t played our best, which gives us confidence.
“I think the guys in general are playing more cohesive hockey together. Guys are starting to find that chemistry that you don’t have to think about. It’s coming a little more naturally. We’re starting to come together as a group.”
NOTES: Penguins captain Sidney Crosby had the secondary assist on Karlsson’s second goal, extending his point streak to eight games (four goals, six assists). He has at least one point in 12 of 13 games this season. … Samuelsson had two shots on goal and three hits in 18:42 of ice time in his return after missing three games with a lower-body injury. Buffalo used 11 forwards and seven defensemen with Samuelsson back. … Jarry’s 16 shutouts are the third in Penguins history, behind Marc-Andre Fleury (44) and Tom Barrasso (22).