"Every game I keep growing and play with more confidence," he said. "Slow production off the start for me. I wasn't used to that but if I kept working hard, good things would happen."
Mangiapane made his playoff debut Thursday, as did six teammates, including linemates Hathaway and Derek Ryan. He admitted to having a few nerves.
"But after the first couple shifts, I started calming down and we started playing more of our line game," he said. "A little bit nervous but I think it was more excitement. I was eager to get going."
The unassisted goal brought Calgary's so-called C of Red out of their seats with a tumultuous ovation, and less than five minutes later, Matthew Tkachuk made it 2-0 with a power-play goal. Late third-period goals by Mikael Backlund, with the man-advantage, and Tkachuk again, into an empty net, completed the scoring.
Mangiapane said he had no idea where his milestone puck has disappeared to, wondering in jest whether someone hadn't already put it up for sale on the internet. (A Flames spokesman said the puck was retrieved and is safe.)
His parents, his girlfriend, a sister and her fiance were in the building when he made personal history Thursday, though he had no idea where in the arena they were sitting.
"They kept it short and sweet," he said with a grin of the message he later received from his parents. "They said, 'Good game.' They don't want to make my head too big."
Mangiapane said he received 10 or 20 text messages from friends and family, and a few former coaches, with his Instagram and Twitter accounts "kind of blowing up."
But on Friday, playoff goal No. 1 was already well behind him, his sights set on Game 2 with a game of postseason experience.