Westfield FFA Cup Final form guide

Good news, Adelaide United fans: Sydney FC can be beaten!

Just over a week out from out the Westfield FFA Cup Final on November 21, the highly-rated favourites were shown to be vulnerable in Round 6 of the Hyundai A-League.

The Sky Blues, who entered the weekend in top spot, were humbled by a hungry Central Coast in a surprise 2-0 defeat in Gosford.

Sydney struggled to cope with the Mariners' tempo and were stung on the counter by Andrew Hoole early, before Jake McGing's second half header sealed the result.

Graham Arnold's side struggled to capitalise on Alan Baro's late sending off and, with concerns raised over the ongoing absence of Adrian Mierzejewski, certainly have room for improvement after their first loss of the season.

The bad news for Adelaide is they have forgotten how to win.

Despite going ahead early against current league leaders Newcastle, United were made to pay for inefficiency up top as they suffered a 2-1 home defeat on Saturday.

That’s three defeats on the trot for Marco Kurz's men, who have one win from six games this Hyundai A-League season. 

While the lively Nikola Mileusnic did end his team's two-match goal drought, Adelaide remain the equal-lowest scorers so far and will find it tough against a tight Sydney defence that has been breached only six times.

The loss of Danish star Johan Absalonsen looms large over the injury-hit Reds, who on Thursday meet a Mariners team they'll surely be consulting for tips on how to spring an upset.

Sydney, meanwhile, will be hoping to reclaim top spot from the Jets in a Saturday night blockbuster at Allianz Stadium.