A power-play one-timer by Hershey's Graham Mink off a Chris Bourque backhanded pass broke a 2-2 deadlock with 7 minutes, 7 seconds remaining in the third period, but the Bears couldn't make the lead stand up.
The Flyers may be without durable defenseman Kimmo Timonen, who is listed as day-to-day with an apparent wrist injury, so speculation centered on Erik Gustafsson as a potential replacement.
"I would say it is highly unlikely that Gustafsson will play for us tomorrow," Holmgren said afterward. The GM also said the same about Gustafsson's defensive partner, Kevin Marshall.
In addition to the uncertain status of Timonen, the Flyers placed defenseman Matt Walker on waivers, but Holmgren said that doesn't mean Walker won't be with the team if he clears waivers.
Gustafsson was recalled by the Flyers on Oct. 27 and played five games before undergoing wrist surgery on Nov. 17.
He was activated from injured reserve and assigned to the Phantoms on Dec. 30. Friday was his fourth game since his return to the Phantoms.
"The first two games I was rusty, to be honest with you, but the last game I thought I played pretty well and today I felt pretty good out there," Gustafsson said. "It is such an exciting event."
Marshall has been called up twice this season, appearing in 10 Flyers games. He most recently returned to the Phantoms on Dec. 20.
As for Harper, he was happily recounting his reaction to his game-winner in front of a larger-than-usual media crowd.
"It's pretty cool and surreal," Harper said. "We knew it would be pretty cool here, but when we stepped out there, everybody on the team was blown away, and one time I looked over at my buddy and said, 'Look how many people are here. It's amazing.' "
Just 28 seconds into the game, Hershey's Bourque banged in a rebound past Michael Leighton to increase his team-leading goal total to 19.
The Phantoms tied it when Mike Testwuide scored an improbable goal with 7:57 left in the first period as his pass from the right circle went off the skate of a Bears player and into the goal.
Contact staff writer Marc Narducci at email@example.com, 856-779-3225, or @sjnard on Twitter.