Thailand, ranked 98 places below Asia’s second-ranked team, threatened a major upset when Teerasil Dangda gave them a stunning lead.
Australia’s trailed to a shock 15th minute strike before coming from behind to claw back a 2-1 victory in their opening match of Group D.
But the Auzy, bidding for their third consecutive finals’ appearance in Brazil in three years’ time, fought back to take all three points with goals from Josh Kennedy and Brosque.
“It feels like a loss,” admitted Australia goalkeeper Mark Schwarzer.
“It was one of our worst performances for a long time and there are no excuses, we weren’t good enough at times, but at least we won which is the positive.”
The Socceroos monopolised the ball in the early exchanges before a wayward pass by Neil Kilkenny gave the Thais the chance to launch a lightning counter attack.
Fast breaking Jakkraphan Kewprom delivered a quality cross which eluded Lucas Neill and travelled into the path of Teerasil, who beat Mark Schwarzer with a neat finish for his 18th international goal.
A rattled Australia searched hard for a response. Brett Holman twice came close while Everton star Tim Cahill blasted over the bar before forcing goalkeeper Sinthaweechai Hathairattanakool into a diving save.
Thai goalkeeper Sinthaweechai Hathairattanakool had frustrated the Socceroos throughout but he presented Kennedy with his simple tap-in.
Concerned coach Holger Osieck used an injury break to talk tactics with skipper Neill while Schwarzer walked to the centre circle to make some forcible points to his midfield.
Australia’s anxieties eased when Kennedy equalised in the 58th minute after Matt McKay’s shot rebounded off Sinthaweechai into the path of the Nagoya Grampus striker to tap home.
Cahill had a goal disallowed four minutes later when he fouled the keeper while jumping for Luke Wilkshire’s corner.
The Australian star player was brought off in the 71st minute for German-based striker Robbie Kruse as the Socceroos desperately chased a winner.
Shimizu S-Pulse striker Brosque was only on the field for seven minutes after coming on for Brett Emerton when he popped up with the winning goal four minutes from the end.
McKay’s cross found Kennedy, who neatly chested down for Brosque to beat the heroic Sinthaweechai much to the relief of the home side.
The Australians take on Saudi Arabia in their second World Cup qualifier in Dammam on Tuesday, while Thailand host Oman in Bangkok.