Alan Brogan's last-gasp goal earned Dublin a dramatic victory over shell-shocked Down as the Dubs secured a place in the Allianz League Final.
Kallum King dropped sub's Bernard Brogan's crossed ball which allowed Alan Brogan to first-time to the net.
Paul Flynn scored Dublin's goal in a superb first half but Down fought back to level at 0-8 to 1-5 at the break.
Down hit three successive points to lead 0-13 to 1-9 and looked the more likely winners before the late drama.
The injury-time goal was a cruel blow for King, the hero at Croke Park in last year's All-Ireland semi-final when he tipped Robert Kelly's goalbound shot on to the crossbar to ensure the Mourne County's passage through to the decider.
King seemed certain to intercept Bernard Brogan's ball across the face of goal but - amid the wet conditions - he dropped the ball at Alan Brogan's feet and there was only going to be one outcome after that.
Down manager James McCartan will feel that it was a game that got away.
Even in the closing two minutes, Martin Clarke and Ronan Murtagh both kicked away possession with speculative efforts when the possession should surely have been retained in an effort to work the ball closer to Dublin's goals.
The teams produced a thrilling first half with Down having the majority of possession against a Dublin side content to counter-attack at pace when the chance presented itself.
Points from Benny Coulter, Paul McComiskey and man-of-the-match Danny Hughes helped Down lead 0-3 to 0-1 but Alan Brogan set up Paul Flynn for Dublin's opening goal as the hosts moved into a two-point lead.
However, a cracking 50-metre Clarke free drew Down level and there remained nothing to separate the sides at the interval with Peter Fitzpatrick among the Mourne scorers.
After Flynn had edged Dublin ahead again, Paul McComiskey was presented with a goal chance after a lightning move but he elected to fist a point.
Down lost goalkeeper Brendan McVeigh to injury early in the second half after he bravely dived at Barry Cahill's feet and came off worst.
Tomas Quinn's free-taking accuracy helped Dublin move into a 1-9 to 0-10 lead but Down responded to regain the advantage with two minutes of normal time left as two Clarke points were split by a towering Conor Maginn effort.
Sub Bernard Brogan lofted a Dublin equaliser as the match entered injury time but there was still plenty of action to follow.
Clarke's attempt to go from a point from a line ball looked unwise and Ronan Murtagh's ball into the Dublin defence seconds later definitely was the wrong option.
It enabled Dublin to work the ball downfield and Bernard Brogan's ball across the face of goal was fumbled by King and Alan Brogan needed no invitation to dispatch the ball into the net.
The Brogan brothers' grandfather Jim died on Friday after a short illness and his memory had been acknowledged by a minute's silence before the throw-in.