First there was his penalty, a blatant dive befitting the waterlogged Allianz Stadium pitch. Then there were two brilliant free kicks, one finding the top corner and the other the bar. The Italian still found time to chime in with a sumptuous assist, showing a quality the Phoenix defence was unable to contain.
That quality appeared unlikely to be exhibited early in terrible conditions in a rain-soaked Sydney. Perhaps unsurprisingly for a side that trains in Wellington, the Phoenix enjoyed the best of the early exchanges as Carlos Hernandez demonstrated the value of raking balls to bypass the unplayable middle of the pitch.
Del Piero had already twice threatened through moments of skill but it was the ugly side of the Italian's game that eventually broke the deadlock - accentuating minimal contact from Jeremy Brockie outside the area, taking another couple of steps into the box and flinging himself to the floor.
Brockie received a booking, Del Piero converted the spot kick, and the Phoenix were left feeling aggrieved. That was quickly illustrated down the other end, when a fired-up Ben Sigmund instigated a fracas for which he also found himself in the referee's notebook.
Del Piero then showed just why he shouldn't have to stoop to football's dark arts, illuminating the muggy evening with a superb free kick curled into the top corner, sending Sydney to the break two goals to the good.
That very nearly became three early in the second spell, when Del Piero hit the bar from an almost-identical position, before the Phoenix found their way back into the game. Nikola Petkovic's challenge on Brockie appeared shoulder-to-shoulder but a generous Kris Griffiths-Jones pointed to the spot and Carlos Hernandez made no mistake.
Any designs the visitors had on a comeback were soon dashed by two stunning goals, though, the first a wonderful team move finished with aplomb by Seb Ryall, the second a tracer bullet into the top corner from Ali Abbas.
Sydney seemed content to see out the result and all that remained was a moment steeped in irony - Del Piero being booked for simulation an hour too late.
Sydney FC 4 (Del Piero 32 pen, 45, Ryall 57, Abbas 60)
Wellington Phoenix 1 (Hernandez 55)
HT: 2-0