After the first three rounds went scoreless, Hedman skated in and snapped a wrister into the left side past Ondrej Pavelec. Evander Kane then tried to sneak a shot between the pads of Mike Smith, but the goaltender came up with the save for the win.
Sean Bergenheim had the lone goal in regulation while Smith stopped 27 shots for the Lightning, who have won two straight.
Rich Peverley scored and Pavelec made 30 saves for the Thrashers, who had won four of five coming in.
Tampa and Atlanta are both at 38 points, two behind Washington for top spot in the Southeastern Division.
Skating shorthanded, Atlanta took a 1-0 lead with 6:04 left in the first. Peverley skated the puck all the way down the right wing and snapped a shot off the post and under the crossbar for his eighth goal of the year.
The Lightning tied the game shortly after an Atlanta power play expired. The puck was cleared down to the Atlanta end and Pavelec tried to play the puck off the backboard. However, he was unable to reach it and Bergenheim was able to grab the puck and slide it past Pavelec before he got back into position with 5:42 left in the second.
There wasn’t much offense in the third period and overtime as Atlanta managed just eight shots during that time and Tampa had five, all of which the goaltenders stopped.
Atlanta hosts Carolina on Thursday…The Lightning host Buffalo on Saturday…The Lightning have won all three games this season and eight straight against Atlanta….Atlanta was 0-for-5 on the power play while Tampa Bay was 0-for-2…Lightning forward Steven Stamkos came into the game having at least a point in 11 straight games against Atlanta, but didn’t record one in this game.
12/15 22:57:19 ET