Perth Glory were unable to claim a home semi-final at Melbourne City's expense as the A-League regular season ended in an avalanche of goals
Perth needed to beat City by four goals to finish above their visitors in fourth and, though their attack fired impressively, their defence let them down in a thrilling 5-4 victory at nib Stadium.
The home faithful were given early encouragement when Neil Kilkenny bundled over Adam Taggart and Diego Castro slotted home the fifth-minute penalty, although Tim Cahill drilled home an equaliser when Bruce Kamau fed the ball into his path.
Andy Keogh headed wastefully wide before the break, but made it 2-1 five minutes into the second period and substitute Chris Harold made an instant impact, heading home to extend Perth's lead after Bruno Fornaroli hit the crossbar.
When another Glory replacement, Neboksa Marinkovic, dispatched a 75th-minute free-kick the improbable was within reach, only for boss Kenny Lowe to see his backline malfunction.
Cahill slid in his second from a Nicolas Colazo cross before his team-mate made it 4-3 and, although Taggart scored a fifth for the hosts, Glory goalkeeper Liam Reddy inexplicably tried to quell a City attack by dribbling into midfield - Nick Fitzgerald converting after Reddy was dispossessed to provide a fitting end to the madness until the sides reconvene in Melbourne
Brisbane Roar also head into the post-season on the back of a thriller, having bounced back from a shoddy first half to beat Wellington Phoenix 4-3.
Roy Krishna put the visitors in front after six minutes at Suncorp Stadium and Michael McGlinchey ended a stunning team move by volleying against the crossbar from 25 yards.
A spectacular long-range strike from Brett Holman levelled matters, but two goals in three minutes from Guilherme Finkler and McGlinchey made it 3-1 to Wellington at the break.
Brandon Borrello curled low into the corner to reduce the arrears in the 51st minute and Jamie Maclaren crashed into the roof of the net to level two minutes later.
Another Holman special ultimately proved decisive and Maclaren - who will share the golden boot with CIty's Fornaroli - missed the chance to claim the award outright when he 76th-minute penalty straight at Lewis Italiano.