Sadly though the other team from Greater Manchester to lose today, Bury going out earlier, meant Rochdale's dream of ending their 36-year stay in the Football League's basement division turned into a nightmare.
Gillingham booked their visit to North London when Simeon Jackson's second half penalty settled a fiercely contested play-off semi-final at the Priestfield.
Having lost out in the play-off final to Stockport 12 months ago, Keith Hill's Dale team harboured hopes of going all the way this time but fell short, their failure to turn around a poor run of form cutting short their pursuit of promotion.
The Spotland outfit went into the game with just one win from their last nine games and, having been held to a 0-0 draw at home in the first leg, faced a tough task against Mark Stimson's strong side which included a trio of ex-Shrimpers, keeper Simon Royce, centre back Garry Richards and, starting on the bench, Mark Bentley, nowadays playing in central defence.
This became even harder when Gills scored the opening goal of the tie in the 13th minute.
There was more than a hint of handball when Dennis Oli charged down Rory McArdle's attempted clearance but referee Michael Oliver allowed play to continue, Oli feeding the ball to Andrew Barcham on the left. He crossed to the near post where Gills' top scorer Simeon Jackson arrived ahead of Tom Kennedy to poke home.
This led to the Kent sides defence sitting deeper and look to hit the away side on the break. Barcham threatened with a run from halfway but chose the wrong option in shooting with support from Oli and Jackson.
With the momentum swinging very much in the home side's direction, the game was turned on its head when Dale equalised before the break.
Goalkeeper Frank Fielding's long punt upfield, flicked on by Thorpe, was chased down by Joe Thompson. He had little chance of winning possession against two Gillis defenders but managed to get in the way of Fuller's clearance, the charge down falling to Chris Dagnall in the box.
The striker fully justified his inclusion in the team ahead of top scorer Adam Le Fondre by checking inside Richards and smashing the ball past Royce. Two ex-Blues with red faces after that!
The goal lifted the visitors and Rochdale made a bright start to the second half only to be pegged back in the 58th minute. John Nutter burst into the penalty area on the left and was hacked down by McArdle, referee Oliver awarding a spot kick.
Jackson stepped forward and sent Fielding the wrong way to put the hosts in the driving seat.
Richards almost extended their advantage when he headed Josh Wright's freekick against the crossbar.
Dale pushed hard for a second equaliser, skipper Gary Jones sending a shot the wrong side of the upright while Ciaran Toner's corner was nodded goalward by substitute Adam Le Fondre, Royce saving well.
McArdle headed Kennedy's cross over, Dagnall had a claim for a penalty waved away and Will Buckley fired across the face of goal as the visitors applied late pressure, but it wasn't to be.
Gillingham manager Mark Stimson said after the game: "I'm very happy for the players. They've put a lot of hard work in this season. The majority of them came back on the first of June - some of them weren't too happy because I cancelled a lot of their holidays, but you get your rewards if you're prepared to do that little bit more. Now they've got their big reward by going to Wembley against a good Shrewsbury side we know about and we look forward to it."
Meanwhile Rochdale manager Keith Hill replied: "There's a lot of emotions in that (dressing) room because we weren't expecting to go out tonight. There's a lot of soul-searching to be done throughout the course of the summer. Not just from me and Flicker (assistant boss David Flitcroft), but from the board of directors, the chairman and the players themselves."
Gillingham: Royce, Fuller, Richards, King, Nutter, Lewis, Wright (Bentley 71), Weston, Barcham, Oli (Southall 84), Jackson (McCammon 90).
Subs Not Used: Julian, Jarrett.
Goals: Jackson 13, 58 pen.
Rochdale: Fielding, Ramsden, McArdle, Stanton, Kennedy, Thompson (William Buckley 61), Toner, Gary Jones, Rundle (Le Fondre 69), Dagnall, Thorpe (Shaw 68).
Subs Not Used: Mark Jones, Holness.
Booked: McArdle, Kennedy, Gary Jones, Stanton.
Goals: Dagnall 36.
Att: 9,585
Ref: Michael Oliver (Northumberland).
League Two Play-Off Final (at Wembley):Saturday 23 May 2009, 15.00.
Shrewsbury v Gillingham