Dunfermline Athletic 1-0 Alloa Athletic (agg 1-3)
Alloa returned to Division One for the first time in 10 years as they beat Dunfermline on aggregate to consign the Pars to relegation.
The Fife side lost 3-0 in the first leg of the play-off final at Recreation Park in midweek.
Alloa, who finished second in Division Two, were again the better team against their full-time opponents.
Allan Smith gave Dunfermline victory, but they will play in the Second Division for the first time since 1986.
For Alloa it meant consecutive promotions, for Dunfermline successive relegations.
Dunfermline, who finished second bottom in Division One, will face Third Division champions Rangers next season.
Two seasons ago, the two sides were competing in the Scottish Premier League.
While Rangers' financial collapse led to a new beginning in the bottom tier this season, Dunfermline's predicament came after an administration that led to them being docked 15 points and having to release eight first-team players.
The youthful side that remained managed to come from 3-1 behind against Forfar Athletic in their play-off semi-final.
However, their 6-1 victory in the second leg after extra-time was assisted by the side finishing fourth in Division Two having three men sent off.
Alloa were not going to make the same mistake under the eye of much-lauded manager Paul Hartley and again were the more incisive side from the start at East End Park.
Former Dunfermline midfielder Derek Holmes came closest with a side-footed effort that curled wide of the far post from 14 yards.
Goalkeeper Jim Hrivnak did well to save at the feet of Kevin Cawley when the speedy Alloa forward broke clear.
Dunfermline eased their way into the game and were peppering the Alloa penalty box with crosses.
However, time again again, brave Alloa bodies found their way between ball and goal as the Pars were unable to test Scott Bain.
Dunfermline manager Jim Jefferies was forced to replace toiling coach John Potter, the defender being replaced with another veteran, striker Craig Dargo, at half-time.
Despite the youth of the other Pars players and Alloa's part-time status, it was the more experienced visitors who looked the fitter side as they took charge again after the break.
Cawley curling a superb effort towards the back post that was turned wide for a corner by the outstretched fingers of Hrivnak, while former Hearts striker Calum Elliot and Ben Gordon both fired wide.
Smith finally forced a fine one-handed save from goalkeeper Scott Bain that sprung Dunfermline into life.
The striker's next act was to chest the ball down before an excellent half-volley from 12 yards found the net.
Dunfermline's hopes effectively ended when former Blackpool midfielder Stephen Husband was shown a red card for a late challenge on ex-Dunfermline midfielder Darren Young with five minutes remaining.
There was still time for Ross Millen and Kerr Young to force saves from Bain, but time ran out on the Pars' 10 men.
Dunfermline : Hrivnak, Millen, Young, Potter (Dargo 46), Whittle, Geggan, Kane, Husband, Falkingham, Smith, Thomson. Subs Not Used: Goodfellow, Byrne, Martin, El Bakhtaoui.
Sent Off : Husband (85). Booked : Falkingham, Geggan.
Goals : Smith 72.
Alloa : Bain, Doyle, Gordon, Marr, Meggatt, Moon, Simmons, McCord (Young 59), Holmes, Elliot, Cawley. Subs Not Used: McDowall, Tiffoney, Grehan, Docherty.
Booked : Meggatt, Gordon, Holmes.
Att : 5,110
Ref : Craig Thomson