Forsberg, the Flyers' biggest offseason acquisition, has four assists in two games. Three have come on goals by Gagne.
"He sees me pretty well on the ice. He's amazing," Gagne said. "He finds me everywhere. He's fun to play with."
The new-look Flyers, who revamped their roster and came in as strong favorites to win the Stanley Cup, evened their record after losing their opener to the New York Rangers on Wednesday night.
Handzus gave Philadelphia a two-goal cushion, beating Brodeur with a shot on the stick side almost six minutes later. Stevenson, a former Devils player, scored on a short-handed breakaway to seal the victory.
"We were tentative, but once we got angry, we got some emotion and we were ready to go," Flyers coach Ken Hitchcock said.
The Flyers and Devils last met in the first round of the 2003-04 playoffs. Philadelphia eliminated its longtime nemesis in five games and went all the way to the seventh game of the Eastern Conference Finals, before losing to eventual Stanley Cup winner Tampa Bay.
New Jersey, which won the Cup in 2003, is trying to overcome losing defensemen Scott Stevens (retired) and Scott Niedermayer (Anaheim).
"The Flyers are so freewheeling, they're able to hit your stick with their glove, just touch you a little bit," Brodeur said. "It's hard to get your position. It's hard to move around the net, especially against a team like that. That's their strength and they use it. They go hard to the net."
Gagne tied it at 2 with help from a video replay late in the second. He wristed a shot that was knocked down by defenseman Richard Matvichuk. But Matvichuk kicked the puck under Brodeur then pulled it out with his glove from behind the goal line. Gagne was awarded his third goal after the replay.
"It was probably between my legs," Brodeur said. "I don't think it was in my lap. I never had it."
Gagne cut the Flyers' deficit to 2-1 midway through the second, backhanding a shot past Brodeur after a nifty pass from Forsberg across the front of the net.
"Gagne's a good goal-scorer," said Forsberg, who led Colorado to two championships, before coming to Philadelphia after the lockout.
Mogilny made it 2-0 with a one-timer off a pass from Martin early in the second. Both of New Jersey's goals were scored with defenseman Chris Therien in the penalty box.
In the first, the Flyers had a goal by Sim nullified because the whistle had blown. Right before that, Brian Savage hit the post with a slap shot.
Niittymaki, who helped the Philadelphia Phantoms win the AHL championship last spring, made 26 saves.
"I think Brodeur is the best goalie in the world," Niittymaki said. "It's always fun to play someone like that. It gives you an extra something."
- Hatcher sat out the second game of a three-game suspension for elbowing Calgary's Matthew Lombardi in the head during the 2004 playoffs when he played for Detroit.
- The Flyers have sold out their first two games.
- The Devils have scored a pair of power-play goals in each of their first two games.