Alessandro Del Piero produced a 27-metre wonderstrike but it wasn't enough as Sydney FC crashed to a 2-1 defeat to A-League strugglers Perth Glory at nib Stadium on Saturday night.Glory goalkeeper Danny Vukovic could only watch on in amazement as Del Piero produced a trademark thunderbolt in the 28th minute to level the score at 1-1 following Chris Harold's earlier strike.But Shane Smeltz's 34th-minute volley was enough for Perth to secure all three points, lifting the Glory back within three points of sixth spot.Sydney, who ended the match with 10 men after Fabio received his second yellow card of the night in the 56th minute, face a major battle to secure a finals spot following back-to-back losses.With four rounds remaining, Sydney remain one point adrift of sixth spot.But with tough games against Central Coast, Melbourne Victory, Western Sydney and Brisbane in the run home, Sydney must rediscover their mojo if they are to make a late charge into the top-six.Glory midfielder Daniel De Silva, who turns 16 next Wednesday, became the second youngest debutant in A-League history when he came on as a 62nd-minute substitute.De Silva, who signed a two-year deal with the club last week, provided the Glory with plenty of energy, and displayed enough talent to justify his tag of being a star in the making.Glory, who entered the match without Jacob Burns (back), Travis Dodd (calf) and Nick Ward (quad), were dealt a further blow when defender Steve Pantelidis was forced off late in the first half with an ankle injury.There were chances galore in the first half, and it was Glory winger Harold who struck first in the 19th minute after a neat midfield run from Liam Miller.Del Piero was a menace from the outset, and the Italian great made Glory pay when he was afforded too much space in the 28th minute.Vukovic hardly moved as Del Piero's swerving strike hit the top corner, but Perth were back in the lead when Smeltz side-footed home a dangerous cross from Scott Jamieson.Although Vukovic could do little to stop Del Piero's goal, he produced a series of sharp saves throughout the match."It was a world-class goal," Glory coach Alistair Edwards said of Del Piero's strike."Even I enjoyed that."There's nothing you can do about those things, apart from close him down a bit quicker."Sydney coach Frank Farina felt his side deserved a penalty when Ali Abbas was brought down early in the match."I thought we had arguably the better chances in the first half, and we had a clear-cut penalty that wasn't given," Farina said."But you can't complain about it - you get some, you don't get some."