It was also Philadelphia goalie Niittymaki's first win since a 3-2 victory over the New York Islanders on Nov. 30, snapping a personal 15-game skid.
"Hopefully we'll play more games against Atlanta," said a happy Niittymaki, who is unbeaten against the Southeast Division leaders, going to 5-0 against the Thrashers in his third NHL season. "Things go pretty well when we play against them."
The Flyers are 16-4-6 against Atlanta, including 8-2-3 at Philips Arena.
Unfortunately for Niittymaki, the Flyers only have two more games left against the Thrashers this season.
"It went pretty well. It was fun to play. I felt pretty good," he said. "I'm one and 15 in my last 16 games now."
The Flyers avoided matching a franchise-record 10 game losing streak, set earlier this season from Dec. 2-27, when Carter scored his sixth goal on a blast from the right circle and over the left-shoulder of Atlanta goalie Kari Lehtonen.
"We've played a lot of close games. We just weren't able to close them out. We talked going into the third period about having a good feeling," Carter said.
"Finally, we got a win. We've been close a lot lately," Flyers captain Peter Forsberg said. "We sat back and let Niittymaki win it for us."
Atlanta's Ilya Kovalchuk, who has four goals in his last three games, opened the scoring on a shot from the right circle that glanced off Niittymaki's left glove and into the net at 11:21 of the first period. It was Kovalchuk's 27th goal.
"It kind of slipped in," Niittymaki said. "I saw it coming. It hit the side of my glove."
The Thrashers failed to capitalize on power plays, going 0-for-6, including a two-man advantage for nearly 2 minutes early in the second period. The Flyers were 1-for-2 with the man-advantage.
"Same old story. Special teams killed us again," Atlanta's Scott Mellanby said. "They had a power-play goal and we didn't score on a power play. We were 5-on-3 for almost 2 minutes. It's just frustrating."
NHL commissioner Gary Bettman was at the game to unveil the logo for next year's All-Star Game in Atlanta at Philips Arena. ... The Thrashers had their fifth sellout (18,598) of the season. ... Atlanta is 4-1 in nationally televised games this season. ... The game was the third of six straight at home for the Thrashers. ... The Flyers won the only other game between the two teams this season, a 3-2 overtime win at Philadelphia on Oct. 26.