Bryan Allen also scored for the Panthers, who are hanging on to slim playoff hopes. Florida is in 12th place in the Eastern Conference and trails eighth-place Montreal by six points with five games left.
The victory was only Florida's fourth in 18 overtimes this season. The Panthers' 14 overtime losses are tied for the most in the league with the Los Angeles Kings.
Vyacheslav Kozlov scored twice for Atlanta, which increased its Southeast Division lead to three points over idle Tampa Bay. Both teams have five games remaining.
Craig Anderson, in goal for Florida after Ed Belfour started a franchise-record 27 consecutive games, stopped 33 shots in regulation and overtime. He then stopped Kozlov and Marian Hossa in the shootout.