Goaltending was a catalyst: Matt Murray totaled 70 saves in the victories at Washington and at Carolina. Casey DeSmith stopped 40 pucks at home vs. Minnesota.
Red-hot Bryan Rust was a factor: He netted twice vs Minnesota, once at Washington. Rust had eight goals in seven games when the holidays arrived.
Sidney Crosby contributed mightily: Three primary assists at Carolina. Crosby set up every goal.
But defenseman Kris Letang credited the Penguins' fortitude, especially after winning on back-to-back nights, away and then home.
"It's a mindset," Letang said. "Against Washington, it's a big rival. It's the Stanley Cup champs. First in our division. It's a measuring stick. You go out there and leave it all on the table.
"[Against Minnesota] was just a grind game. They're a solid team, and they play really structured. So it was important for us to stay in the moment and stay with the game plan."
Coach Mike Sullivan's game plan involves plenty of Letang.
Letang has been excellent to date: Eight goals, 20 assists and a plus-8 mark in 34 games. His 28 points rank seventh among NHL defensemen. He leads the Penguins in ice time with an average of 26:20, the second-highest mark for Letang's career so far.
The win at D.C. may have been Letang's best effort of the season.
The Penguins were reduced to five defensemen in the game's first minute after Jamie Oleksiak was injured in a fight. Letang played 32:22, assisted on a goal, and was plus-1.
Letang was often matched against Capitals sniper Alex Ovechkin. Ovechkin entered the game with a six-game goal-scoring streak and a 14-game points streak. Those both ended.
"If somebody goes down, everybody has to step up," Letang said. "Washington, obviously, is a big rivalry. We know all the history.
"Obviously, we all know about Ovechkin's shot. You have to take his time and space away. But if you can get under his skin and stay in his face...he's a guy that bring so much energy, and he's emotional on the ice. But sometimes that can work against you."
Letang's workload was a bit lighter against Minnesota: He skated 26:37 and was plus-2.
Letang played 25:20 at Carolina, scored the game's first goal and was plus-1.
The Penguins' penalty kill was perfect in the three victories before the holiday break: 11-for-11. Letang has long been a regular participant on the PK, but lately he's been joined by top-six forwards Crosby and Jake Guentzel, both serving unaccustomed duty.
"Before, we had set guys that were going over the boards [on the PK]," Letang said after the Pens beat the Wild. "But our team is built on different components ... you saw Sid and Guentzel kill penalties. It kind of scares the other team. They're not so ready to make cross-ice passes, because if Sid picks it off, you have to defend against him.
"So we're changing things, but the structure is there."
Mark Madden hosts a radio show 3-6 p.m. weekdays on WXDX-FM (105.9).