Alexander Frolov gave the Kings a 3-1 lead with 10:36 to play, scoring his second of the game at the end of a 2-on-1 break with Craig Conroy. But the Flyers capitalized on two giveaways in the Kings' end to pull even.
Mike Knuble knocked the puck off defenceman Lubomir Visnovski's stick and it bounced right to Simon Gagne, who beat Dan Cloutier from close range with 6:47 remaining. Just 40 seconds later, Umberger stole the puck from Dustin Brown at the top of the left circle, whirled around and beat Cloutier as Flyers forward Mike Richards provided a screen.
The Flyers completed their improbable comeback when Richards' centring pass caromed off the left skate of Kings defenceman Mattias Norstrom and right to Umberger, who swept his sixth goal past Cloutier with 3:37 left.