On a record-breaking night at the Bluetongue Stadium in Gosford where the equal most number of goals in an A-League fixture were scored, it was actually Sydney, missing their key man in Alessandro Del Piero due to a hamstring injury, who broke the deadlock through Yairo Yau in the eighth minute.
But Tomas Rogic's strike, an own goal from Sebastian Ryall and McBreen's penalty put the Mariners in charge before half-time.
Ali Abbas halved the deficit but Michael McGlinchey and Rogic put the hosts 5-2 in front before McBreen added further gloss to the triumph.
Substitute Chris Harold's strike five minutes from time helped Perth Glory record a third straight home win after they defeated Newcastle 3-2.
The visitors took a sixth minute lead through Calvano Tiago but Steve McGarry levelled soon after while Nick Ward's strike seven minutes before the interval put Perth in the ascendancy.
Josh Mitchell levelled in the 71st minute but Harold's late strike ensured Perth leapfrogged Newcastle into third, one point shy of Central Coast and behind Adelaide in second on goal difference.