(Brighton 1-2 Swindon; agg 2-2, Brighton win 4-3 on penalties)
Brighton reached the Division Two play-off final after a dramatic penalty shoot-out victory over Swindon.
Victory was sealed when Andrew Gurney's spot-kick hit the post.
A poor game sprang into life on 81 minutes when Swindon's Sam Parkin tapped in from close range to take the match into extra-time.
Swindon looked like they were going to Cardiff when Rory Fallon slotted home only for Adam Virgo to level the tie in stoppage time with a diving header.
The sides were greeted by driving rain, thunder and lightning before kick-off and the conditions seemed to affect the teams in a disappointing first half.
Brighton's defence was always on top and Mooney's chip over the bar just after the half-hour mark was Swindon's first real effort on goal.
81 mins: Parkin levels the aggregate score for Swindon
97 mins: Fallon gives Swindon the lead
120 mins: Virgo equalises for Brighton
Pens: Gurney hits the post to hand Brighton victory
However, they almost took the lead in the closing stages of the opening period through Mooney's powerful header but Virgo made a goalline clearance.
The second half started in much the same fashion as the first with both sides getting plenty of men behind the ball after losing possession.
In the 71st minute Nathan Jones' cross found Adam
Hinshelwood at the back post but his shot was well parried by Swindon keeper Rhys Evans.
With the match opening up, Mooney had a glorious chance on 78 minutes but his 25-yard thunderbolt hit the bar.
Swindon finally got the breakthrough when Sammy Igoe's fine shot was parried by Ben Roberts and Parkin was able to tap in from close range after a goalmouth scramble to send the match into extra-time.
The strike stunned the Brighton faithful and things got even worse seven minutes into the first extra period when Mooney's pass released Fallon and his shot slid under Roberts into the net.
And just as Swindon thought that they were assured a trip to Cardiff, Virgo produced a stunning diving header in stoppage time to take the tie to penalties.
The sides were locked at 2-2 in the shoot-out when Mooney missed his kick to put Brighton in charge.
Virgo's successful kick put the pressure on and Gurney fired his kick onto the post to send the Withdean Stadium into raptures.
Brighton: Roberts, Virgo, Cullip, Butters, Harding,
Reid (Hart 48), Oatway, Carpenter, Nathan Jones (Piercy 90),
Knight (Hinshelwood 66), Iwelumo.
Subs Not Used: Kuipers, Mayo.
Swindon: Evans, O'Hanlon, Smith (Nicholas 90), Heywood, Gurney,
Igoe (Reeves 105), Miglioranzi, Howard (Fallon 72), Hewlett,
Subs Not Used: Griemink, Pook.
Booked: Hewlett, Fallon.
Referee: G Laws (Tyne & Wear).