In doing so, the home side bounced back in fine style from last week's thrashing at the hands of league leaders Brisbane Roar, and inflicted Sydney's first loss in five games.

Three goals in the first 23 minutes, including two inside the first five minutes, set up the Gosford-based side for the much-needed victory.

Strike pairing Adam Kwasnik and Matt Simon scored the early goals, giving the Mariners their first win in five matches.

An own goal by Sydney's Sebastian Ryall in the first minute of the second half capped a forgettable night for last season's Hyundai A-League champions.

The scoring spree started before most of the 7,160 fans had taken their seats, when Kwasnik slammed the ball in the back of the net after just 28 seconds.

The play was started by dynamic midfielder Mustafa Amini, who played in Simon beautifully down the right flank. The lanky striker sent in a wicked low cross and Kwasnik made no mistake from close range.

Moments later and Kwasnik turned provider when he sent Josh Rose on a run, before the left-back knocked in a dangerous looking ball for Simon to tap home amid a fumble from Sydney goalkeeper Ivan Necevski.

Clearly stunned by the events of the opening few minutes, Sydney looked to provide a response in the 10th minute with Mark Bridge getting on the end of a lofted Terry McFlynn ball. But the 25-year-old striker's header was saved comfortably by Matt Ryan.

Indeed, it would be the home side that would add to the goals tally, and again it was Kwasnik and Simon who would cause the damage on 23 minutes.

Simon's cross from the left should have been dealt with easily by central defender Hayden Foxe, but the Sydney stopper missed his clearance, allowing Kwasnik the easiest of tap-ins for his second brace in Mariners colours.

No doubt Sydney mentor Vitezslav Lavicka gave his charges plenty to think about at the half time break, but the Mariners again came out in fierce fashion, claiming their fourth goal with only 17 seconds played in the second stanza.

This time Foxe's defensive partner Sebastian Ryall was guilty of mistiming a Simon cross, slicing his kick horribly past a helpless Necevski.

Terry Antonis and Dimitri Petratos, both making their Hyundai A-League starting debut for the Sky Blues, had chances to pull a goal back late in the game, but the youngsters were unable to hit the target as the Sydneysiders slumped to their worst defeat of the season.

The heavy loss leaves Sydney struggling to stay in touch with the top six on the ladder as they prepare for this Tuesday evening's AFC Champions League draw.

Central Coast Mariners 4 (Kwasnik 1', 23', Simon 5', Ryall og 46')
Sydney FC 0
Crowd: 7,160 at Bluetongue Stadium