Daniel McBreenâ€™s first-half header was the difference as the Heart battled with ten men for much of the second half after Michael Beauchamp was sent off.
It was the second time this season the Mariners have defeated the Heart 1-0 from a headed goal, following their meeting at AAMI Park in Round 1.
Venue: Bluetongue Stadium, Gosford
Crowd: approx. 6,000
Referee: Peter Green
Yellow cards: CCM - John Hutchinson 76â€™, Adam Kwasnik 78â€™
MH - Dean Heffernan 23â€™
Red cards: MH - Michael Beauchamp 52â€™
Most of the opening 15 minutes saw the Heart play with just ten men due to key defender Michael Beauchamp receiving treatment for a bloodied nose but the Mariners were unable to really push their opponents despite their advantage.
GOAL They did, however, take the lead in the 20th minute when Michael McGlinchey found Pedj Bojic by himself in the area before the defender chipped to the back post where Daniel McBreen netted with a customary header for his second goal in two matches.
The goal rattled the Heart who began to make fundamental errors but they managed to settle things down as the half went on and managed to go into the dressing room a goal down despite losing Beauchamp to more treatment in the final few minutes.
The visitorsâ€™ job got much harder in the 52nd minute when Beauchamp was sent off after a tangle with Central Coastâ€™s Oliver Bozanic. The reasoning for the dismissal was not very clear but the two certainly clashed in the Mariners penalty area and referee Peter Green had no hesitations in showing the central defender a straight red.
That gave the Mariners a real â€˜inâ€™ but they were unable to add to their one-goal cushion for most of the second half as the Heart went about trying to save the match.
Graham Arnold would have been frustrated his side were making things difficult for themselves and could not put the game away whilst John van â€˜t Schip would be disappointed with the loss but pleased his side showed plenty of spirit to stay in the contest to the final whistle.
Mathew Ryan (gk), Pedj Bojic, Alex Wilkinson, Patrick Zwaanswijk, Joshua Rose, Rostyn Griffiths, Michael McGlinchey, Oliver Bozanic, John Hutchinson, Daniel McBreen (Mrdja 84â€™), Matt Simon (Kwasnik 70â€™)
Subs - Paul Henderson (gk), Brad Porter, Nik Mrdja (84â€™), Adam Kwasnik (70â€™)
Clint Bolton (gk), Michael Marrone, Simon Colosimo, Michael Beauchamp, Dean Heffernan, Matt Thompson, Brendan Hamill (Babalj 46â€™), Wayne Srhoj, Nick Kalmar (Hoffman 59â€™), Gerald Sibon (Aloisi 69â€™), Aziz Behich
Subs Peter Zois (gk), Jason Hoffman (59â€™), Eli Babalj (46â€™), John Aloisi (69â€™)