Raffl cut the Flyers' deficit back to one in the final minute.
"We bent a little, but didn't break," Tampa Bay coach Jon Cooper said. "It was good to see."
Stamkos put the Lightning ahead 2-1 during a power play with 45.7 seconds remaining in the second period. He has 16 goals and 25 points in 21 games against Philadelphia.
"They have a good power play with Stamkos shooting everything," Voracek said. "Dangerous. I would say it was a couple of tough goals, but that's the way they saw it. We could do nothing about it, just maybe focus, try to kill it."
Namestnikov redirected Anton Stralman's blue line shot past goalie Ray Emery for a 1-0 lead 3:29 into the game. Stralman has eight assists and nine points in 11 games this season after getting 13 points over 81 games last season with the New York Rangers.
The Flyers went almost 10 minutes before Claude Giroux got their initial shot on goal. Simmonds tied it 1-1 and stopped his five-game point drought when he beat Ben Bishop on a rebound goal with 7:17 left in the first.
Tampa Bay's Tyler Johnson had his seven-game assist streak end. The center had 11 assists over the stretch.
NOTES: After the game the Flyers announced that they had signed 31-year old unrestricted free agent defenseman Carlo Colaiacovo. The team is without injured defensemen Braydon Coburn and Andrew MacDonald. ... Flyers C Vincent Lecavalier said he is close to returning from a foot injury that has sidelined him seven games. ... Tampa Bay RW Ryan Callahan, who has missed five games due to a lower body injury, could play Saturday against Washington. ... Philadelphia D Brandon Manning, recalled Wednesday from Lehigh Valley of the AHL, played in his first NHL game since the 2012-13 season and had an assist.