GCU have now set up a meeting with Central Coast Mariners for a chance to play Brisbane Roar in the Grand Final.

The visitors took the lead in the first half before coming from behind in the second after the Reds had gone in front with goals from Sergio van Dijk and Mathew Leckie.

After a tentative but entertaining opening Adelaide finally carved out half a chance after a thrown in deep in attack.

Andy Slory cut the ball back to the penalty spot where van Dijk and Travis Dodd were lurking but neither could muster a shot on goal under the pressure of the GCU defence.

A minute later and Shane Smeltz almost opened the scoring when Reds stopper Dario Bodrusic failed to clear a long ball out of defence from Gold Coast.

The Croatian was unable to get his foot to the clearance and Smeltz ran onto the pass before baulking past Bodrusic and firing low from inside the box as he looked for the bottom corner.

Reds keeper Eugene Galekovic was equal to the task and stopped the shot but could do little about the Kiwi's next effort as Smeltz picked out the top corner from 30 metres.

On 38 minutes, the GCU striker received the ball with his back to goal, turned, took a touch and burnt off his defender before blasting his shot past the out-stretched Galekovic.

Slory was replaced five minutes before the break after picking up an injury in a challenge and Leckie came on and made an immediate impact with his explosive pace.

The Young Socceroo helped set up van Dijk in the dying stages of the half but his shot flashed past the post.

GCU could have doubled their advantage just after half-time when Dino Djulbic got his head to the ball from a set piece.

The defender's header bounced off the post and Galekovic was forced to slap the ball away from danger.

In the 54th minute the Reds grabbed an equaliser from the penalty spot when van Dijk was fouled in the box by Bas van den Brink after a Cassio corner.

Van Dijk stepped up and converted the spot kick, sending GCU keeper Glen Moss the wrong way.

Adelaide took the lead 10 minutes later when Leckie pounced to smash in the rebound after Moss had saved Cassio's shot.

Marcos Flores had fed Cassio the ball with a brilliant one-touch pass and the Brazilian fired directly at the GCU shot stopper from close range with Leckie following through.

A minute later and the visitors scored a dramatic equaliser with former Adelaide striker Bruce Djite heading into an empty net.

Tahj Minniecon raced down the left and after his initial cross was cleared, the speedster whipped in a second.

Smeltz got on the end of the cross and his close range header was saved by Galekovic, but only into the path of Djite who didn't miss with the goal at his mercy.

With 10 minutes remaining GCU stole a dramatic third when substitute Shane Porter was brought down in the area by Nigel Boogaard.

Smeltz had played a delightful dummy to allow Porter to run onto the ball before being felled by the Reds stopper.

The Kiwi had to take his spot kick twice after an infringement on the edge of the area, but it mattered little as Smeltz secured the victory for Gold Coast.

Adelaide United 2 (van Dijk 56' pen, Leckie 70')
Gold Coast United 3 (Smeltz 38', 79' pen, Djite 71')
Crowd; 15028 @ Hindmarsh Stadium