A superb first half from Adelaide United and a towering injury-time header was enough to see off the 10-man Brisbane Roar 2-1 at Suncorp Stadium on Saturday afternoon.
Jeronimo Neumann had put the visitors deservedly ahead in the first term, following through on a penalty which he had initially failed to score, before substitute Besart Berisha netted a slickly-worked equaliser with 10 minutes remaining.
Deep into injury time, with Brisbane pushing for a winner, a fabulous header from Adelaide sub Jordan Elsey secured a thrilling upset win for Josep Gombau's side.
Brisbane right-back Diogo Ferreira received his marching orders in the 40th minute after notching his second yellow card to leave his struggling side with plenty of work to do.
In the early stages it was clear Adelaide had put an imprecise Brisbane off their game, and their superiority was rewarded when they won a penalty in the 20th minute.
Jeronimo exploited a lapse in concentration from a dawdling Shane Stefanutto to snatch the ball with just clear space and Theo in front of him.
The Brisbane goalkeeper slid in and caught the Argentinean with a trailing leg to concede a penalty and earn a yellow card, which could well have been red as he appeared to be the last defender.
Theo did well to save Jeronimo's penalty kick with his legs, but he was unable to prevent the ball rolling just out of his reach, and the Adelaide attacker darted in to poke the ball into the net for the opening goal.
Minutes later, Theo raced out of his box dangerously to snuff out another United raid, managing to just shepherd the ball away from Steven Lustica.