The Brazilian playmaker looked set to enjoy a dream European debut with a stunning first-half double but the Italian champions ruthlessly hit back to expose the holders' defensive deficiencies to snatch a deserved draw in an enthralling Group E encounter.
Arturo Vidal pulled a goal back before the break and, after Eden Hazard was denied what appeared a penalty, Fabio Quagliarella came off the bench to equalise and was a lick of paint from completing a sensational turnaround.
That would have been cruel on Chelsea but - as in their UEFA Super Cup thrashing by Atletico Madrid - they left themselves exposed enough to make such an outcome possible.
It was all looking so good after 33 minutes of what Roberto Di Matteo on Tuesday dubbed Mission: "Impossible".
His Midas touch in the competition was in evidence again after the shock selection of Oscar, who he admitted the club might not have convinced to join them had they not ended their agonising wait for Champions League glory.
Chelsea fans still pinching themselves at last season's astonishing triumph were given another glimpse of the European Cup before kick-off when members of the armed forces were handed the honour of parading it.
That proved a prelude to a combative first half-hour, which left David Luiz with a bloody nose and Vidal needing treatment on a knock.
The quality of football on show was not exactly what Chelsea owner Roman Abramovich had paid £80million to see but there were glimpses of the drama to come.
Luiz was under just enough pressure to steer Frank Lampard's corner straight at Gianluigi Buffon, while Fernando Torres wasted a great breakaway opportunity after robbing Andrea Pirlo, who is said not to have had a great start to the season by his high standards.
Torres, looking more lively than in his wretched performance at QPR on Saturday, also went close with a header but Juventus carved out the first clear chance when Andrea Barzagli's crossfield ball put Claudio Marchisio one on one with Petr Cech, who came flying out to smother.
Mirko Vucinic should have also done better than fire Vidal's pass into the sidenetting when clean through in the 29th minute and he was made to pay dearly in the next four minutes.
Oscar, who had almost looked like he had been picked to shadow Pirlo, found himself in space 25 yards out and unleashed a drive that Gianluigi Buffon would surely have saved but for a telling nick off Leonardo Bonucci.
If the first was lucky, the second was sublime, Oscar expertly controlling Ashley Cole's pass with his back to goal before spinning and unleashing an unstoppable dipping curler into the top corner.
But Juve are not 42 games unbeaten in Serie A for nothing.
Marchisio almost broke through again and Vidal fired over before taking full advantage of slack defending to drive a low left-foot shot into the bottom corner.
Hazard wasted another breakaway before half-time, after which Chelsea cranked up the pressure, with Branislav Ivanovic's dipping shot just kept out by Buffon.
The goalkeeper also beat away Lampard's driven free-kick before the home side were denied a penalty when
Hazard surged into the box and went down under a clumsy challenge from Barzagli. Referee Pedro Proenca simply told Hazard to get up and he arguably made another mistake when booking Ramires for a perfectly clean tackle.
Vidal deservedly saw yellow for hauling back Oscar but Juve were suddenly on top, Chelsea resorting to the sort of counter-attacking tactics that served them so well last season.
Ramires was withdrawn for Ryan Bertrand before Oscar - who was stood on making a tackle - departed for Juan Mata.
Juventus responded by sending on Quagliarella for Sebastian Giovinco, who was actually looking a real threat.
And after Hazard and Mata almost combined to finish the contest - the latter blasting into the side-netting - the Juve substitute equalised.
It was another defensive horror show from Chelsea, Luiz hopelessly out of position as Quagliarella burst into an acre of space between John Terry and Ivanovic to steer Pirlo's through-ball between Cech's legs.
It was a nerve-jangling finish and Quagliarella was desperately unlucky not to complete an incredible turnaround when his left-foot curler clipped the crossbar.