Brisbane Roar dealt Western Sydney Wanderers' top six ambitions a huge blow while improving their own chances of finals football by beating the Red & Black 2-1 on Friday night in Parramatta.
Warren Moon's Roar are poised to leapfrog the Wanderers on the ladder after Japanese forward Riku Danzaki netted the winning goal in first half stoppage time.
It came after Bruce Kamau cancelled out what was Brisbane defender Josh Brindell-South's first A-League goal to open the scoring.
The result means Brisbane are only two points off sixth-placed Western Sydney, but with with three matches in hand over Carl Robinson's side.
The Wanderers, who are now without a win in their previous five A-League fixtures, are at risk of tumbling out of the six altogether because finals-chasing Brisbane, Western United, Wellington Phoenix and Perth Glory all have games in hand on them.
Western Sydney play Melbourne Victory next Friday night before hosting Sydney FC in a season-defining Sydney derby on Saturday May 1.
Brisbane will aim to boost their top six credentials further against Perth next Sunday.
Brisbane made the ideal start in this pivotal clash through an unlikely source - Brindell-South, who coolly fired home the scraps after Wanderers gloveman Daniel Margush had dived low to his left to parry Dylan Wenzel-Halls' drive.
It was the former Wellington Phoenix player's maiden strike in the competition.
Brisbane should have doubled their lead in rapid fashion only for Wenzel-Hallls to head Corey Brown's ball over from point blank range.
It proved a costly miss for Roar, as the Wanderers secured the equaliser in the resulting play.
It came when Mitch Duke contested Margush's goal kick and emerged with the ball, before playing in Simon Cox who squared for the unmarked Kamau to place the ball in the top corner.
Wenzel-Halls spurned another opportunity by pulling his finish across the face after being played in by Jay O'Shea, as Margush kept Macaulay Gillesphey's header out and O'Shea was denied a goal of the season contender when his effort from inside his own half crashed back off the crossbar.
Brisbane did regain the lead their enterprise deserved when a brilliant first-time cross from Joey Champness was tapped home by Danzaki at the back post in first half stoppage time.
The Wanderers toiled in search of an equaliser with Jamie Young required to tip over Kwame Yeboah's header and the Brisbane goalkeeper pulling off a fine reflex stop to deny Dylan McGowan.
Young stood tall to deny Kamau from firing in at the near post in injury time as the Wanderers were left needing to breathe new life in their top six campaign.