Institute have winger Stephen Curry to thank as they saw off a battling Ballyclare Comrades 3-1 at the Riverside Stadium.
The win sets up a two legged encounter against Carrick Rangers with a place in the Danske Bank Premiership next season.
The home side scored the all important opening goal on 18 minutes as Sammy Morrow’s flick released Jamie McIntyre and the winger, made no mistake slotting the ball past Comrades keeper Paddy Flood.
Just after the half hour Morrow had a great chance to double ’Stute’s advantage, but with only a stranded Flood to beat, the striker’s attempted lob sailed wide.
Flood was called into action on 55 minutes as Stephen Curry sees his left footed strike tipped over by the Comrades keeper.
From Michael McCrudden’s resulting corner Mark Scoltock seen his goal bound shot saved by Flood, before Comrades cleared the danger.
Institute doubled their advantage on 62 minutes as Stephen Curry latched onto Morrow’s flick before firing home.
Moments later Comrades, who knew an away goal would be massive, went close as substitute Jason Johnston saw his left footed strike superbly saved by Martin Gallagher.
The Londonderry men added a third on 71 minutes as Curry nipped in to win possession and blasting home past Flood.
Comrades made it a nervy finish as they pulled a goal back on 87 minutes as substitute Johnston turned the ball after John Dobbin’s strike came back off the post.
Institute: Gallagher, Roddy, O’Donnell, Scoltock, D Curry; S Curry, Foy, Grace (McDermott 88), McIntyre (Devlin 90); McCrudden (Brown 81), Morrow.
Ballyclare Comrades; Food, Brown, Woods, Youle, Gray; O’Hanlon (McIlveen 75), Dobbin, McMullan, Robinson (Taggart 72); Trussell, Lynch (Johnston HT).
Referee: Peter McGrath