Ronan Hayes provided the super sub impact at Parnell Park where Dublin turned a three-point deficit into a dramatic three-point win with a late surge of scoring.
Already beaten by Offaly once this season, a crucial National League loss at Croke Park two months ago, Niall O Ceallachain's charges looked set to suffer the same agony all over again.
But a burst of late scoring that included 1-01 from sub Hayes turned a tricky situation into a hugely important win that gives Dublin a strong platform from which to attack the rest of the provincial campaign.
In all, Dublin outscored Offaly by 1-04 to 0-01 from the 68th minute to keep alive their hopes of at least a top-three finish this season.
Conor Donohoe, John Hetherton and the excellent Brian Hayes, Ronan's brother, grabbed the other late points as Dublin turned the screw impressively.
Sean Currie finished as their top scorer with nine points and they will hope for a similar outcome next weekend when they return to the Donneycarney venue to play Wexford in Round 2.
As for Offaly, they'll be glad to see the back of this ground. This was their first Leinster championship game since 2018 when they were relegated following a defeat to Dublin at the same venue.
Johnny Kelly's side will take plenty from this performance though as they battled bravely and had goalscorers in Oisin Kelly and Killian Sampson while Brian Duignan hit 0-08. They will host Galway in Round 2 next weekend.
Offaly went with 14 of the team that lined out against Waterford in the Division 1B league decider, starting David King instead of Colin Spain at midfield.
Dublin, meanwhile, were considerably changed from the side that started their last league game against Laois.
Captain Chris Crummey returned to the team for starters while Paddy Dunleavy, former All-Star Danny Sutcliffe and Diarmaid O Dulaing were all late additions to the team.
Eddie Gibbons made his first Championship start in goals for the hosts, returning to the team after missing the last two league games.
It looked initially as if Dublin had got the mix right as they opened up with some fluid hurling, working the ball cleverly through the lines and imposing their physicality.
Donal Burke twice pointed as the hosts opened up a 0-05 to 0-02 advantage, with the threat of more to come.
It didn't pan out like that though as Offaly hauled themselves back into the game, thanks in scoring terms to Kelly who netted in the 14th minute to level the game but moreso through a general upping of the ante and intensity throughout the field.
Offaly struck four points in a row between the 21st and 26th minutes to lead by 1-07 to 0-07, making it crystal clear that they intended on making serious capital gains.
Kelly's goal was relatively straightforward, a long delivery breaking kindly for the Belmont man to strike first time from the ground to the net.
But the wing-forward, tracked by Dublin's Dunleavy, had to dig deeper into his arsenal of scoring options for a 28th minute point from tight up against the left endline.
Ravenhill, whose monster free at Croke Park won the league game for Offaly in February, blasted two more long-range scores while Duignan and Charlie Mitchell came alive inside.
It all added up to a 1-10 to 0-11 half-time lead for Offaly who were just about good value for it.
Dublin did have a couple of first-half goal chances from Donal Burke and Cian O'Sullivan but both were comfortably dealt with. Ross Ravenhill tracked Burke in open play, Offaly captain Ciaran Burke marked O'Sullivan and Padraig Cantwell man-marked Currie.
Currie was Dublin's liveliest attacker in the opening half, clipping four points and two from play.
Dublin took a brief lead after the restart, drilling three points in a row from Currie, Crummey and Conor Donohoe.
But, just like earlier, it was a false dawn as Offaly responded with Sampson's 40th minute goal to prove yet again that they wouldn't back off.
Sampson emerged from a ruck of players with the ball for Offaly's goal though Dublin 'keeper Gibbons will be frustrated he didn't stop it.
Offaly kept the pressure on throughout the second-half and points from the likes of Duigan, Ross Ravenhill and Dan Bourke helped them open up a 2-18 to 0-21 lead with two minutes of normal time remaining.
That's when the scores dried up, however, as Dublin brought all their big game experience to bear with that late run of scores.
Dublin: Eddie Gibbons; Andrew Dunphy, Paddy Smyth, John Bellew; Paddy Dunleavy, Chris Crummey (0-01), Paddy Doyle; Conor Burke (0-02), Conor Donohoe (0-03); Cian O'Sullivan, Brian Hayes (0-03), Donal Burke (0-04, 2f, 1 65); Sean Currie (0-09, 5f), Diarmaid O Dulaing (0-01), Danny Sutcliffe.
Subs: Ronan Hayes (1-01) for Sutcliffe 23, Darragh Power for O Dulaing h/t, Fergal Whitely for Donal Burke h/t, John Hetherton (0-01) for Whitely 51, Andrew Jamieson Murphy for O'Sullivan 63.
Offaly: Mark Troy; Ben Conneely, Ciaran Burke, Padraig Cantwell; Ross Ravenhill (0-01), Donal Shirley, Jason Sampson; Cathal King, David King; Killian Sampson (1-02), Dan Bourke (0-01), Oisin Kelly (1-01); Dan Ravenhill (0-05, 3f), Brian Duignan (0-08, 6f), Charlie Mitchell (0-01)
Subs: Eoghan Cahill for Mitchell 51, Colin Spain for David King 55, Cillian Kiely for Ross Ravenhill 58.
Referee: Johnny Murphy (Limerick).
