On a night where the Socceroos continually failed to take their chances in front of goal, South Korea went ahead on the counter attack midway through through the first half with a lovely finish by Hwang Ui-Jo, despite being under constant pressure in the early stages.
The green and gold had countless opportunities to force an equaliser but it took until literally the last kick of the game as Luongo prodded home from point-blank range after debutant Martin Boyle forced the ball from the South Korea goalkeeper's fingertips.
Graham Arnold made three changes to the team that won 4-0 against Kuwait last month, with Mat Ryan and Aaron Mooy coming into the team, while Jamie Maclaren made this third start for his nation.
Australia, with full backs Josh Risdon and Aziz Behich bombing forward, began the match on the attack and it took only three minutes for Tom Rogic to blaze over the bar from outside the area.
After several half chances were squandered, Mooy had a golden chance to open the scoring but his volley from just inside the box skewed high and wide when you expected a player of his quality to hit the target.
Just when it looked least likely, South Korea took the lead on 22 minutes after a long ball over the top saw Hwang nick in behind Trent Sainsbury to sprint through on goal and finish cliniically past Ryan.
The visitors continued this method with balls in behind Sainsbury and new skipper Mark Milligan, but the Australian defenders dealt with the danger more confidently as the match went on.
Rogic and Mathew Leckie had shooting chances to tie up the game before the break but both drilled their efforts straight into the arms of Kim Seung-gyu.
Australia continued to make all the play in the second half but the profligacy remained in front of goal.
Leckie failed to slip through Rogic when a better pass was needed and Maclaren had the ball in the back of the net but Robbie Kruse was correctly flagged for being offside in the build up.
The introduction of Awer Mabil in the second half for Kruse livened up the Socceroos attack, with the former Adelaide United man setting up a chance for Rogic and he had an effort blocked after being put through by the Celtic playmaker.
It could have been all over for Australia with 20 minutes to play, but Ryan made a world class save from Ju Se-Jong's free kick to keep the home side alive.
With Australia pushing numbers forward in the 94th minute to snatch an equaliser, Rogic's shot from outside the area was fumbled by Seung-gyu under pressure from substitute Boyle, with Luongo on hand to tap in the empty net and secure Australia a deserved result.