Sydney FC lost a second A-League match in succession for the first time since 2016 on Saturday and had their lead at the top of the table cut to five points by Newcastle Jets.
Returning to action domestically for the first time since a 2-1 defeat at Newcastle, and on the back of two winless AFC Champions League outings against Kashima Antlers, Graham Arnold's men went down 2-1 at home to Brisbane Roar.
Captain Matt McKay and Jacob Pepper – the latter scoring his first A-League goal since 2012 – were the unlikely heroes for Brisbane as they capitalised upon poor set-piece defending from Sydney inside the opening 20 minutes.
That proved to be a theme of the match, with Sydney centre-back Alex Wilkinson having a header ruled out for offside from Adrian Mierzejewski following a VAR review before Milos Ninkovic converted an in-swinging delivery from Jordy Buijs in the 59th minute.
Substitute Matt Simon crashed a shot against the near post in the 89th minute and stabbed into the side netting during seven minutes of stoppage time but an equaliser proved elusive.
Earlier on Saturday, Newcastle won 1-0 at Wellington Phoenix.
Right-back Jason Hoffman barrelled into the box in the 43rd minute and fired a volley through the grasp of goalkeeper Tando Velaphi at the second attempt.
It means Ernie Merrick's Jets retain hopes of preventing Sydney from retaining their status as premiers – something that appeared more or less a formality at the start of this month. But, with a run of one win in seven in all competitions, Sydney's Champions League struggles have bled unhelpfully into their domestic form.