Alessandro Del Piero's A-League debut has ended in defeat after Sydney FC went down 2-0 to an impressive Wellington Phoenix at a wet and windy Westpac Stadium on Saturday.

Goals in either half to Belgian import Stein Huysegems and 19-year-old striker Louis Fenton were just reward for the Phoenix's control and patience.

Wellington turned on a spectacular welcome for Del Piero with a southerly wind hitting the stadium an hour before kickoff.

The heavy rain and strong winds eased, and the Phoenix started strongly in chilly conditions, creating plenty of chances but converting only one to lead 1-0 at halftime.

Sydney lacked cohesion and although former Juventus star and Italian World Cup winner Del Piero showed some nice touches, but there was little for him to work with for much of the first spell.

Belgian import Stein Huysegems provided a genuine goal threat for the Phoenix up front, but there were other options in the elusive Benjamin Totori and former Newcastle striker Jeremy Brockie.

Totori hit the woodwork with a screamer after a crisp interchange between Fenton and Brockie, then a Huysegems header forced an excellent save from Sydney stopper Ivan Necevski.

Captain Andrew Durante's header found the back of the net in the 35th minute but the goal was disallowed after Ben Sigmund was adjudged to have impeded Necevski.

The deadlock was broken just two minutes from halftime when Manny Muscat's through ball found Huysegems, who finished clinically.

Sydney came close soon after, Mitchell Mallia forcing an excellent save from Mark Paston just before the break.

The Aussies came out with more intent in the second spell, coach Ian Crook signalling his intent in bringing on young Panama striker Yairo Yau and attacking midfielder Ali Abbas as the hour mark approached.

But Wellington continued to create chances, Paul Ifill drawing an excellent reflex save from Necevski barely a minute after he came on at 60 minutes.

Fenton thudded home a superb diving header with just on 15 minutes left, connecting to a pinpoint cross from Muscat, and the Phoenix controlled the closing minutes for a well-earned win.