The Packers (10-3) earned their fifth consecutive victory to stay a game up on Detroit in the NFC North. Atlanta dropped to 5-8, but remained in a first-place tie with New Orleans in the woeful NFC South.
Julio Jones had a career-best 259 yards receiving for the Falcons before leaving with a hip injury. Jones had a 22-yard touchdown catch in a 20-point fourth quarter that helped Atlanta cut into Green Bay's big lead.
But the Packers recovered the ensuing onside kick. James Starks' 41-yard run with 1:37 left to the Atlanta 6 effectively ended the Falcons' upset hopes.
Atlanta came frustratingly close to a rare victory in Titletown. Green Bay held on for its seventh home win, but the porous pass defense may have given potential playoff foes some hope that Lambeau Field may not be that impenetrable after all.
The Falcons did damage even with Jones hobbling on the sideline, appearing to favor his left side.
Ryan threw for 375 yards and four scores, including a 1-yard touchdown catch by Roddy White with 6:20 left that trimmed Green Bay's lead to 40-30.
Mason Crosby kicked a 53-yard field goal with 4:37 left, helping the Packers withstand Atlanta's final punch.
Rodgers finished 24 of 36 for 327 yards. Lacy had 73 yards on 13 carries, and 33 yards on five catches.
The tough running back wiggled from side to side to celebrate his 1-yard touchdown reception with 4:20 left in second quarter. The score was set up by safety Morgan Burnett's interception of Ryan.