In a game that turned out to last 3-hours, 27-minutes and many questionable decisions from replacement officials and long clock stoppages, Denver (1-1) had turnovers on four on its first five possessions
, but the Falcons (2-0) didn't put the game away until they converted a third down with 2 minutes remaining and ran out the clock.
The NFL's only four-time MVP, completed 24 of 37 for 241 yards, one touchdown, the three picks and a 58.5 passer rating.
finished the game completing 24 of 36 for 219 yards, two touchdowns and a 101.5 passer rating.
The Broncos got a big boost from running back Willis McGahee
, who finished with 113 yards on 22 carries. McGahee scored two 2-yard touchdown runs in the fourth quarter as Manning tried to rally Denver from a 20-point deficit.
finished with 78 yards receiving on eight catches, including a 17-yard TD that cut the lead to 20-7 with 6 seconds remaining in the first half.
The Broncos' franchise dropped to 7-26 in Monday road games and Manning dropped to 11-4 on Monday's.
The Falcons snapped a six-game losing streak on Mondays and improved to 1-4 under coach Mike Smith.
Atlanta hadn't won on a Monday since Dec. 12, 2005 against New Orleans.