Juventus stunned Champions League holders Chelsea as Fabio Quagliarella's late strike rescued a dramatic 2-2 draw at Stamford Bridge and ruined Oscar's command performance for the Blues on Wednesday.
Oscar marked his first start for Chelsea with an impressive brace that included a stunning solo effort to fire Roberto Di Matteo's side into a 2-0 lead before half-time in their Group E opener.
But the Brazil midfielder's heroics were in vain thanks to a gutsy recovery from the Italian champions, who reduced the deficit before the break through Arturo Vidal and salvaged a point with 10 minutes left thanks to Quagliarella's clinical finish.
While Blues boss Di Matteo, who splashed out £25 million to sign Oscar from Internacional during the close-season, will have been encouraged by his new recruit's eye-catching display, it was Chelsea's defensive frailties that were the defining factor.
"We found ourselves in a great position to win the game and we only got a draw but we knew we were playing a quality side," Di Matteo told Sky Sports.
"We feel a little deflated because we were ahead but it's going to be a tough group."
Asked about Oscar's performance, Di Matteo added: "We were just waiting for the right game for him, it was wonderful to watch. The second goal was fantastic."
The Champions League trophy was paraded around Stamford Bridge by military personnel just before kick-off. And the fond memories of their final triumph over Bayern Munich in May seemed to inspire Di Matteo's side as they set the early tempo.
But Juventus had a glorious chance to snatch the lead against the run of play midway through the half.
Andrea Barzagli floated a long pass over the top of the Chelsea defence and Claudio Marchisio's run evaded the offside trap, yet, with only Petr Cech to beat, the midfielder's first touch was poor and he could only poke a shot straight at the Chelsea goalkeeper.
There was more confusion in the Chelsea back-four soon after when Branislav Ivanovic carelessly conceded possession to Vidal, who slipped a pass through to Mirko Vucinic. The Juventus striker had a clear sight of goal but dragged his shot wide.
Chelsea made the visitors pay for their profligacy in the 31st minute as Oscar opened the scoring.
Eden Hazard slipped a pass to Oscar 25 yards from goal and the Juventus defence made the fatal mistake of standing off the Brazilian. He took full advantage with a powerful strike that a crucial deflection off Leonardo Bonucci as it flashed past Gianluigi Buffon.
Oscar took the spotlight again just two minutes later. With his confidence sky-high, the Brazilian collected Ashley Cole's pass on the edge of the penalty area and fooled two Juventus defenders with a sublime flick to make space for a magnificent curling effort that raced into the top corner of Buffon's goal.
At that point Chelsea were rampant, but their lack of defensive solidity allowed Juventus back into the match in the 38th minute.
When Vidal took possession 30 yards out, he should have been closed down by the Chelsea rearguard. Instead they allowed the midfielder to advance to the edge of the area and drill a low strike past Cech.
It took a fine stop from Buffon to keep Juventus in with a chance early in the second half as the veteran goalkeeper pushed away Ivanovic's dipping shot, while Juan Mata, on as a substitute for Oscar, fired into the side-netting.
But Juventus, back in the Champions League after a three-year absence, were unbeaten in their last 42 Serie A games and they showed the spirit that characterised that epic run to snatch a dramatic equaliser in the 80th minute.
Di Matteo's men were the authors of their own downfall.
John Obi Mikel made the first mistake as he surrendered possession and then Luiz and John Terry were caught trying to play offside, allowing Quagliarella to ran onto Marchisio's pass and guide a clinical finish under Cech.
Quagliarella could even have won it for Juventus in the final moments, but his looping shot clipped the crossbar.