|Del Piero leads the celbrations as Juventus pick up a famous win at the San Siro stadium [AFP]
Juventus threw the Italian championship wide open by sealing a surprise 2-1 win at AC Milan as evergreen forward Alessandro Del Piero became the club's all-time top Serie A scorer.
The home side started at a furious pace on Saturday but Fabio Quagliarella silenced much of the San Siro with a perfect header after 24 minutes.
The goal completely knocked the stuffing out of Milan and Del Piero struck midway through the second half to better 1950s great Giampiero Boniperti and move on to 179 top-flight goals for Juve.
Milan's Zlatan Ibrahimovic headed in to halve the arrears with his first goal against one of his former Italian sides but Juve clung on to move two points behind the third-placed Rossoneri and four adrift of shock leaders Lazio.
The Romans face a difficult trip to Palermo on Sunday while Inter Milan, in second, won 1-0 at Genoa on Friday to leave the table looking perfectly poised after two months.
"I have a group who work, who always give everything they've got and the results are seen on the field, " Juve coach Luigi Del Neri, whose side had a sticky start to the season after last season's shock seventh-place finish, told Sky TV.
"As I always say, Juve shouldn't depend on one player but one Juventus."
Del Piero, 35, only started because of injuries to Amauri and Vincenzo Iaquinta but like so often in his glittering career, he saved his record-breaking goal for the biggest stage.
Substitute Mohamed Sissoko slipped after breaking into the box but the ball fell for Del Piero who made no mistake.
The Juve captain, the club's record scorer in all competitions and record appearance holder, was substituted with five minutes left and although a few Milan fans tried to whistle, they were quickly drowned out by widespread applause.
Quagliarella, the man many Juventus supporters did not want to buy, put the visitors in front when he planted a header right in the corner from Paolo De Ceglie's whipped cross.
The goal-shy Italy striker arrived in the close season from Napoli after Juve had failed with bids for at least two other forwards and fan forums labelled him a desperate signing.
He made them eat their words with an excellent all-round display, something few Milan players could manage.
Ibrahimovic hit the post from distance and blasted over a great chance at 0-0 but the wheels suddenly came off and owner Silvio Berlusconi sat in the stands with arms crossed.
Massimiliano Allegri's side have to rediscover their early spark when they entertain Real Madrid in the European Champions League on Wednesday but injuries continue to weigh.
Ronaldinho was not quite fit enough to feature after thigh trouble while defender Daniele Bonera went off with suspected knee ligament damage.
Juve's injury problems are even worse with centre back Giorgio Chiellini pulling up before kick off and De Ceglie and winger Jorge Martinez going off with knocks.