Alessandro Del Piero put the Sky Blues in front in the 43rd minute at Allianz Stadium while Serbian striker Ranko Despotovic struck just three minutes later on the way to Sydney climbing to third on the ladder.
Harry Kewell had a chance to get one back for the Heart with a second-half penalty but sent his shot wide.
Michael Mifsud gave the visitors hope with a goal in the 72nd minute but the Heart couldn't find the equaliser.
Del Piero and Kewell were yet again denied a showdown, missing each other by a matter of minutes when Del Piero was taken off at halftime and Kewell came on in the 56th minute.
Del Piero, who missed last week's loss to Central Coast with a hamstring strain, was said to have been feeling tightness and taken off as a precautionary measure.
What had been shaping as an entertaining clash boasting two big names began as a mundane affair devoid of any intensity and desperately needing something to spark it into life.
That spark finally came in the 42nd minute, courtesy of none other than Del Piero.
The Italian legend easily weaved past two defenders to deliver a superb goal to the delight of most of the 16,008 frustrated fans.
The Sky Blues capitalised on a deflated Heart side to double the advantage just moments later and go to the break 2-0 up.
Despotovic fired his shot low and hard that was too good for the diving Andrew Redmayne who could do nothing to thwart the effort.
The Heart began the second stanza with a sense of urgency, with the likes of Andrea Migliorini, David Williams, Golgol Mebrahtu and Mifsud threatening Sydney keeper Vedran Janjetovic.
And the chances kept coming for the Heart, who were awarded a penalty in the 67th minute when a Nick Kalmar shot came off the hand of Joel Chianese.
Kewell stepped up to the mark but to his own horror and that if his teammates fired it straight into the crowd.
But Mifsud made no mistake moments later when he found himself in plenty of space in front of goal and with Janjetovic off his line easily got one back.