It was his 76th NHL goal, tying him with Brian Bellows and Wayne Gretzky for the third-most by a teenager, behind Jimmy Carson (92) and Dale Hawerchuk (85). Laine turns 20 on April 19.
"He's a special young man, 19 years old and still growing into his body, really competitive guy, wants to score," Jets coach Paul Maurice said. "He's going to be a good Winnipeg Jet for a long time."
Giroux gave the Flyers a 1-0 lead at 5:40 of the second period during a delayed penalty. He jumped in as the extra attacker, took a pass from Valterri Filppula and found an open spot on the left side of the offensive zone.
Giroux has seven points (two goals, five assists) during a six-game point streak.
"I saw [Filppula] going backdoor and I was looking to pass the whole way," Giroux said. "Lucky enough the fans were yelling at me to shoot, so I just tried to find a hole and it went in."
MacDonald made it 2-0 at 8:01 of the second period. Officials ruled Hellebuyck made the save on a backhand from the right side, but video review showed the puck crossed the goal line and play was stopped less than a minute later.
"I was more mad I missed it on the rebound after it came out of [Hellebuyck's] glove," MacDonald said. "I thought I should have had that one. I got to the bench and [Giroux] mentioned it was in and within seconds they blew the horn. Nice feeling to be able to chip in like that."