Shane Walsh was the Galway hero as his ninth point of the game with the final kick saw his side edge Armagh by 2-22 to 0-27 in a thriller at Kingspan Breffni Park.
Heading into the game, Armagh knew they were straight through to the quarter-finals as winners of Group Four, but Galway's continued interest in the All-Ireland Senior Football Championship was far from secure.
Those prospects looked bleak at the end of the first half when they trailed by eight, having been outplayed with two penalties in the process.
But they roared back into it after the break with goals from John Maher and Rob Finnerty injecting life as they grabbed the win which ultimately saw them claim third place in the group, which means they hit the road next week for a preliminary quarter-final.
Although Armagh came into this repeat of last year's All-Ireland final with the pressure off, they were full of intent early with Ethan Rafferty slinging over the first of his team's four two-pointers in the opening period.
Rian O'Neill and Peter McGrane followed with points before Galway were offered a great chance to get into the game when awarded a ninth-minute penalty as Rob Finnerty went down under a Paddy Burns challenge, but Rafferty was equal to Matthew Tierney's effort and John Maher screwed the rebound wide.
Shane Walsh did get them on their way with a pair of scores, but Armagh were flying with the next five points including a two-pointer from Niall Grimley.
Peter Cooke slung over a two-pointer for Galway, but Darragh McMullan hit back in kind with a scorching effort with the outside of his boot.
The gap was eight when Galway got a second penalty on 30 minutes with Walsh going down under a challenge from Burns and this time, Finnerty stepped up but thumped over.
Eight was the gap at the break as Rafferty got his second two of the half, this time a free, as Armagh went in with a 0-15 to 0-7 lead that in no way flattered them.