Swindon Town will meet Preston North End in the League One play-off final after a pulsating 5-5 draw earned them a 7-6 aggregate win over Sheffield United.
Mark Cooper's men headed into Monday's semi-final second leg with the advantage after a 2-1 victory at Bramall Lane last Thursday, but were made to sweat for their place at Wembley in a hugely exciting encounter.
Swindon had the better of a breathless opening to the game, with Ben Gladwin's double inside the opening 10 minutes seemingly putting them in complete control of the tie.
United were given a glimmer of hope immediately after Smith's strike when Swindon's Nathan Thompson deflected Jamie Murphy's shot past his own keeper.
And the visitors' fightback continued before the break when Chris Basham netted with a fantastic diving header to reduce the arrears to two on aggregate.
Swindon's Jonathan Obika scored a brilliant individual effort to put daylight between the teams again with six minutes to go.
But United were not finished, as Matt Done and Che Adams set up a grandstand finale by drawing them level on the night at 5-5 and just one down on aggregate.
However, Nigel Clough's side were unable to complete a remarkable comeback in eight minutes of injury time as Swindon edged their way to Wembley in the most dramatic of circumstances.
