Adelaide United held Perth Glory to a 1-1 draw at Coopers Stadium on Friday that leaves the visitors' top-four hopes looking slim.
The A-League champions enjoyed the better of the chances but were unable to restore their advantage after Diego Castro cancelled out Dylan McGowan's opener in the first half.
The result sees Adelaide climb two points above bottom-of-the-table Central Coast Mariners, while Glory could be six points adrift of fourth - and the home elimination-final that would bring - should Melbourne City and Bribane Roar win their respective games in hand.
McGowan responded to a glaring earlier miss when he broke the deadlock after 23 minutes, heading home from close range after Taylor Regan had glanced Marcelo Carrusca's corner onto the post.
Castro levelled the match in stoppage time at the end of the first half, sending goalkeeper Eugene Galekovic the wrong way from the penalty spot after McGowan was penalised for a foul.
Adelaide were angry at the way Castro went to ground to win the penalty and pushed to restore their advantage after the break, but they found keeper Liam Reddy in good form.
Glory deserved a point but the result means they could find themselves sixth if Western Sydney Wanderers beat Newcastle Jets on Saturday.