Central Coast Mariners stun Melbourne City in A-League Men's ...

The Central Coast Mariners are A-League Men champions for just the second time in their history after Jason Cummings scored a hat-trick in a 6-1 grand final annihilation of Melbourne City.

Cummings, who looks set to take up a mega-money move in India, signed off from his stint in Gosford in style by leading the club to their first title since 2013.

The Socceroos forward opened the scoring in the first half before dispatching two second-half penalties at Sydney's Western Sydney Stadium in front of a crowd of 26,523.

Sammy Silvera, Beni Nkololo and Moresche also found the back of the net for the Mariners on Saturday as they recorded the biggest grand final victory since 2007.

The Mariners fans could not believe what they were seeing.(ABC News: Brendan Esposito)

Substitute Richard van der Venne was the only player to find the net for premiers City, who have now been in the past four grand finals but have just one championship to their name.

City began strongly with Danny Vukovic forced into a low save to thwart Socceroos winger Marco Tilio but things began to unravel when midfielder Valon Berisha collided with the Mariners goalkeeper.

With Berisha hobbling, the Mariners smelled blood and surged downfield through French winger Nkololo who found Cummings in the box.

Curtis Good did well to block Cummings' first shot but the striker was too sharp with the follow-up, firing past Tom Glover in the 20th minute.

Jason Cummings opened the scoring for Central Coast and ended up with a hat-trick as the Mariners won the Championship.(Getty Images: Scott Gardiner)

City subbed Berisha off for van der Venne but the Mariners were attacking at will.

Marco Tulio and Nkololo forced Glover into fingertip saves, but there was nothing to prevent Silvera burning past Nuno Reis on the left and finishing to make it 2-0 after 34 minutes.

City looked shell-shocked but somehow finished the first half with a goal, Jamie Maclaren slipping the attention of the Mariners defence and pulling the ball back for van der Venne to fire past Vukovic.

The goal before half-time seemed to shake City into action and they began the second half with intent as Mathew Leckie and van der Venne both went close to equalising.

Mariners boss Nick Montgomery turned to his bench, sending on homegrown leftback Jacob Farrell shortly after the hour mark.

Farrell had an immediate impact as he was felled by Andrew Nabbout in the City box in the 64th minute, with referee Chris Beath pointing to the spot.

Cummings sent Glover the wrong way and soon had another opportunity from the spot when Callum Talbot handled a Farrell cross.

Socceroos star Jason Cummins was in scintillating form.(ABC News: Brendan Esposito)

The Socceroos forward fired to the right to wrap up his hat-trick and the Mariners hadn't finished there.

City's resolve wilted and the Mariners were queuing up to score, Silvera setting up Nkololo from an inch-perfect cross before Brazilian striker Moresche completed the rout.

AAP