Del Piero double downs Toon
The Magpies are now without a point after three games in Group E and now need three wins from their final three games just to have an outside chance of scraping through to the next phase.
Two second half strikes from the prolific Del Piero were enough to seal the game for The Old Lady as the increase their lead at the top of the group.
Kieron Dyer caused early problems for the homes side and he set up Alan Shearer in the first minute and Lillian Thuram needed to make a crucial block.
Pavel Nedved then went close for Juventus three minutes later when his header flashed just wide of Shay Given's left-hand post.
Laurent Robert had Gianluigi Buffon scrambling for his looping volley that just cleared the bar with still only six minutes played.
Marco Di Vaio, who scored twice in Juve's last game, was then carried off the field and placed straight into an ambulance after falling under a challenge from Andy O'Brien.
The Italian striker landed on his chest and required several worrying minutes of treatment before he left the field on a stretcher with an oxygen mask after struggling with his breathing.
Juve coach Marcelo Lippi was able to underline the strength of his squad by bringing on David Trezeguet for the stricken Di Vaio, to almost immediate affect.
The French target man shaped his body superbly to volley towards goal to force Given into a agile tip over the bar.
Former Monaco man Trezeguet then anticipated the knock down from the resulting corner only to fire over from close range.
With Juve finding their feet, Alessandro Del Piero had his first sight of goal when Newcastle's defence backed off the Italian superstar who unleashed a left-footed effort that crashed against the bar with Given beaten.
Del Piero caused problems again five minutes before the break when his free kick from the left only just eluded the arriving Mark Iuliano with Given struggling.
Arguably the best chance of the half came to the visitors in the second minute of stoppage time.
Dyer blasted through the defence down the right towards the touchline before cutting the ball back for Shearer, who's fluffed shot fell for Robert who volleyed towards goal from eight yards only for Buffon to repel the shot with a superb reacting save from point-blank range.
Buffon started off the second half in less convincing fashion as he flapped hopelessly at a Robert corner but was helped out by his defence who cleared.
Trezeguet nearly profited from a great cross from Davide Baiocco on 51 minutes when he arrived at the back post but for the ball to trickled just wide of the post under pressure from O'Brien.
Juve then got the breakthrough in the 64th minute when Greek defender Nikos Dabizas was adjudged to have pulled back Del Piero right on the edge of the box.
With the Italians claiming a penalty, Del Piero took full advantage and planted the resulting free kick in the top corner leaving Given with no chance and even avoiding Dabizas who had backed up onto the goal line.
Dabizas was also booked to make matters worse, and will miss the visit of Juve to St James' Park in the next group game.
Shearer thought he had levelled just three minutes later when he powered a trademark header past Buffon but the goal was chalked off as Dyer was in an offside position in the middle of the box.
Sir Bobby Robson made his last throw of the dice with a double substitution with ten minutes left but a minute later it was all over.
Good work from Edgar Davids down the left fed Nedved who put in another good cross that was dummied well by Trezeguet for Del Piero.
Del Piero steadied himself before firing past Given, with the help of slight but crucial deflection on the way into the net.
The goal added to Del Piero's impressive haul this season, and in the competition as he continues to make ground up on Raul as Champions League top scorer, with his double taking his tally to 27 in 50 appearances.
The other game of the group between Feyenoord and Dinamo Kiev ended goalless in Rotterdam.
Neither side were able to make the breakthrough at De Kuip and the result extends Juve's lead at the head of the group and leaves Newcastle with the slimest of chances of making a dramatic comeback to qualify from the group.
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