"I knew it was coming hard," Ladd said. "He doesn't necessarily put it that soft."
"I was real happy with our effort," said Florida coach Peter DeBoer, whose team made eight trades last month. "I was proud of how we started the game. We played right until the buzzer."
Florida came in ranked 28th in the NHL in scoring, and Atlanta had only seven goals in the previous five games. Then the teams combined for four third-period goals.
Ladd gave the Thrashers a 2-1 lead with 18:52 left in regulation before Wheeler added his second goal, and 14th this season, less than 5 minutes later.
"We got down two goals, but we pushed back and scored two goals," Florida goalie Tomas Vokoun said. "We're trying to do the best we can. We traded for a lot of guys. That's stuff you can't control. It's really tough."
Weiss' 18th goal came on the power play with 12:02 remaining. Booth added his 18th to make it 3-3 just 3 minutes later.
Byfuglien assisted on all four of Atlanta's goals, giving the All-Star defenseman 31 this season. On the winning goal, he passed from the right circle across the slot to Ladd, whose 25th goal was a tip-in to Vokoun's glove side.
Last season, Ladd and Byfuglien teamed to help Chicago win the Stanley Cup. This season, they're fighting to keep Atlanta, which began the night as the No. 11 team in the Eastern Conference, in the playoff hunt.
"We definitely needed it," Ladd said. "We found a way to win. It's a big relief. It feels like we should be getting a bonus."
On Ladd's first goal, the Atlanta captain passed from the red line across the slot to a charging Tobias Enstrom. The puck bounced off Enstrom and caromed to the right side where Ladd had moved into position for a wraparound goal.
Ladd has nine goals and one assist in his last 11 games.
Florida, which began the game with the NHL's third-best, penalty-killing unit, spent most of the second period on its heels. The Panthers killed four penalties, including Jason Garrison's 4-minute high-sticking infraction, but they registered just two shots in the second -- both in the final 1:08.
Bryan Little, who hit the right post when shooting at a nearly wide-open net with 1:20 left in regulation, assisted on Ladd's winner.
Atlanta went 2-2-1 on its five-game homestand despite scoring no goals in the first period and just one in the second.
Samsonov's 11th goal, a tip-in, gave the Panthers a 1-0 lead at 5:46. It was his first goal in three games since being traded from Carolina.
Wheeler made it 1-1 by tipping in a rebound 43 seconds into the second.
"We have been putting up 40-plus shots a night for about two weeks straight," Wheeler said. "At some point, it has to break. Tonight was one of those nights we did all the right things. Guys got in front and we found the goal."
Chris Mason stopped 31 shots to improve to 9-10-3 for Atlanta. Vokoun made 32 saves.
Panthers defenseman Niclas Bergfors, who was dealt from the Thrashers to Florida last Monday, was disappointed his new team didn't maintain its fast start.
"You have to play the whole game," Bergfors said. "We had a good start. We battled. We got a point. That gives us a little boost."
Florida failed to earn its first three-game season sweep at Atlanta since the Thrashers joined the NHL for the 1999-2000 season.