Matt Simon scored against his former club in injury time as Sydney FC left it late to avoid dropping points away to Central Coast Mariners in the A-League on Saturday, while Melbourne City cruised past Western Sydney Wanderers.

Reigning premiers and champions Sydney, seeking to retain both of their titles, led through Milos Ninkovic's goal in the 32nd minute in Gosford, the midfielder stooping to nod Paulo Retre's cross from the right past goalkeeper Ben Kennedy.

The Mariners were reeling from the sudden departure of coach Paul Okon earlier this week, but they managed to equalise through Jake McGing's close-range finish with eight minutes to go.

Led by caretaker boss Wayne O'Sullivan, the hosts even threatened to snatch all three points and spring an upset, only for Simon, who starred for Central Coast in two different spells, to meet a deflected, looping cross and head home the winner for Sydney at the back post in the 93rd minute.

The victory sends Sydney eight points clear of second placed Newcastle Jets, who lost 5-2 at Adelaide United on Friday, while the Mariners remain second bottom.

In the other match on Saturday, captain Michael Jakobsen scored his first league goal for Melbourne City to help seal a 3-0 home win over Western Sydney.

Bruno Fornaroli opened the scoring in the 42nd minute and set up Stefan Mauk's classy 67th-minute effort either side of Jakobsen's header from Luke Brattan's corner, as Warren Joyce's side climbed above local rivals Melbourne Victory and into third place, strengthening their grip on a finals berth.

The Wanderers are at risk of dropping out of the top six if Brisbane Roar win away to bottom side Wellington Phoenix on Sunday.