The Flyers had a goal by Konecny overturned at 7:01 after the Panthers successfully challenged for offside, and Verhaeghe made it 2-0 at 8:38 on a breakaway.
Nick Seeler cut it to 2-1 at 16:31 with a backhand for his first goal of the season.
"I thought we did a lot of good things," Seeler said. "We knew they were going to come out hard in the first. You know, it's their home opener. We knew that. They got a couple quick [goals] and we showed some resiliency again, which is positive. But there were a few breakdowns that led to a few untimely goals, which hurt us."
Sandstrom stopped Tkachuk on a short-handed breakaway in the first minute of the second period, and James van Riemsdyk tied it 2-2 with a power-play goal at 15:16 on a rebound.
Balcers scored at 3:51 of the third with a high backhand after taking a pass from Bennett, and Josh Mahura made it 4-2 at 9:08.
"Obviously it is exciting to get the win here in the home opener," Mahura said. "I did exactly what I wanted to do. It's exciting for our team. It was awesome, we had a lot of energy out there, and I thought we played a pretty good 60-minute game."