Dave Bolland's goal at 4:21 of the third had tied the scored at 4-4.
Patrick Sharp had a goal and two assists and Antti Niemi was 23-of-27 in goal for Chicago, which has won three straight following a three-game losing streak. Marian Hossa and Kim Johnsson also scored for the Blackhawks.
Tobias Enstrom, Evander Kane and Maxim Afinogenov scored second-period goals to bring the Thrashers back from 3-1 deficit. Jim Slater also scored for Atlanta and Ondrej Pavelec stopped 35 shots for the Thrashers.