Mile Jedinak's deflected free kick and two penalties overcame Honduras - and 29 gruelling months - to secure play-off qualification to a fourth-straight World Cup.
Australia's resounding victory, on the back of a goalless draw in the first leg of the sides' CONCACAF/AFC Play-off second leg, takes the team to a fourth successive World Cup.
Maynor Figueroa pulled a goal back in the fourth minute of stoppage time, scrambling home from a corner, but it was of little consolation to a Honduras side who will watch from the sidelines as Australia take on the world at Russian Federation 2018. "We knew it was always going to be a hard qualifying campaign but this makes it very, very special".
Jedinak stepped up to the spot to complete his hat-trick, although there is lingering doubt over whether the captain's first was put down as an own-goal to Figueroa.
Australia make the breakthrough eight minutes into the second half when Jedinak's free-kick from just outside the penalty area took a massive deflection off substitute Henry Figueroa to beat a wrong-footed Escober.
"It's been a tough two-and-a-half years to get to this point but we did it".
Now, three and a half years later, those same players have taken Australia to yet another World Cup, and how they perform in Russian Federation will be the most crucial indicator of just how many fruits Postecoglu's efforts have bared.
Australia, however, remained on the offensive as Cahill's looping header dropped onto the crossbar. - Socceroos skipper Mile Jedinak.
Honduras were finally forced to chase the game but Australia pulled further clear when Jedinak put his second penalty into the opposite corner after Robbie Kruse had been brought down by Johnny Palacios five minutes from time.