Thanks to their superior goal difference, United knew a draw in their final game of the season would be enough after Sydney FC Youth could only draw with Central Coast Mariners Youth on Saturday.

With their fate in their own hands, Mike Mulvey's young troops produced a sterling performance to cement fourth place on the ladder, but they had to come from behind after Adelaide took a first half lead courtesy of Evan Kostopoulos's strike inside the first ten minutes, albeit against the run of play.

Gold Coast had the better of the early exchanges with a string of corners and free-kicks causing danger for the home defence, but Kostopoulos took advantage of a rare breakaway and his 20-metre effort was too hot for Gold Coast 'keeper Jerrad Tyson to handle.

Losing a goal only seemed to fire United up even more as they continued to dominate possession and press for the leveller, which despite their best efforts, failed to materialise before half-time.

Trailing at the break and with just 45 minutes to resurrect their finals ambitions, United came out with all guns blazing after Mulvey tinkered with his formation to engineer a way past the dogged Adelaide rearguard.

The reward finally came in the 56th minute thanks to the enigmatic Tahj Minniecon. James Brown was the architect of the move, releasing Minniecon with a deft pass that invited the speed machine to run at the home defence. Minniecon skipped past two defenders before homing in on goal and firing confidently past Codey Larkin.

It was end-to-end stuff for the rest of the contest with United's central defensive pairing of Ben Wearing and Dino Djulbic holding firm, while at the other end, Minniecon, Brown and Chris Harold were a constant menace.

The result means United face a sudden death semi-final next Saturday, away at newly-crowned National Youth League Premiers, Central Coast Mariners. The game will be held at Pluim Park, Gosford, with kick off at 3.00pm Queensland time (4.00pm AEDT).

The victors will progress to the Grand Final and meet the winners of the other knockout semi-final between second-placed Perth Glory Youth and third-placed Adelaide United Youth.