Rantanen left for a brief time early in the third period after getting hit in the mouth by the stick of the Flyers' Michael Raffl. He was fine except for a swollen top lip.
"I tried to counter-hit him but he got his stick up high," Rantanen said.
The Avalanche were playing with 11 forwards because Rocco Grimaldi and Matt Nieto were sick, so coach Jared Bednar said it made things easier when he saw Rantanen come back to the bench.
"I think we got fortunate there," Bednar said. "He took that shot and you never know what's going to happen. Turned out to be nothing so he's back on the bench. You never want to play two short there, especially when you've got back-to-back [game] coming the next night. [You] don't want to wear guys out. … [It] was a little bit concerning, but when he came back it was a little bit of a sigh of relief."
Jakub Voracek had a goal and an assist for the Flyers (7-6-2), and Valtteri Filppula, Claude Giroux and Dale Weise scored. Neuvirth made 23 saves.
The Flyers came from behind three times this season to get one point, so despite the loss they remain a confident bunch.
"We get down a goal we don't just pack it in and feel sorry for ourselves," said defenseman Shayne Gostisbehere, who had an assist in his return after missing three games because of an upper-body injury. "… I think it's how we've been responding, that's the biggest thing. Our confidence level is through the roof because we just keep going and keep making plays."
Voracek tied the game 3-3 at 4:33 of the third period when he tapped in Travis Sanheim's shot that deflected off linemate Sean Couturier, but Yakupov put the Avalanche ahead 4-3 at 5:37.
Weise tie it 4-4 when he finished a give-and-go with Jordan Weal at 6:37.