Tkachuk and Drake Batherson scored 31 seconds apart in the third period. Tkachuk made it 4-1 at 13:07 on a backhand before Batherson split the defense and scored on his own backhand to extend it to 5-1 at 13:38.
“They're too good to give that team that many good looks. Well, not that many, but the looks they got were really good,” Pittsburgh defenseman Marcus Pettersson said. “Our energy was good from the start, but we were down 2-0. I think we got a little frustrated in our structure and kind of lost it and gave them good looks that they capitalized on."
Jake Guentzel scored from the high slot with 34 seconds remaining for the 5-2 final.
"I think you never want to lose, but I thought the first two periods were good from our end," Guentzel said. "Obviously in the third, we pressed a little bit. ... Some positives to take out of it. Just have to bear down."
NOTES: Crosby (five), Rust (five), Evgeni Malkin (four) and Reilly Smith (four) have scored 18 of the Penguins’ 23 goals this season. … Senators defenseman Nikolas Matinpalo played 8:24 in his NHL debut after being recalled from Belleville of the American Hockey League on Saturday. … Ottawa defensemen Thomas Chabot and Erik Brannstrom did not play after being injured in a 3-2 loss to the New York Islanders on Thursday. Chabot is expected to miss 4-6 weeks because of a broken right hand; Brannstrom is out indefinitely with a concussion. … Hellberg was recalled from Wilkes-Barre/Scranton of the AHL on Wednesday after goalie Alex Nedeljkovic sustained a lower-body injury in a 4-1 loss to the Dallas Stars on Tuesday.