Oscar made a goalscoring impact on his competitive Shanghai SIPG debut, helping to secure a 3-0 victory over Sukhothai in the AFC Champions League play-offs.
Shanghai spent €60 million to sign the Brazil international from Chelsea, and the midfielder went some way to repaying part of that fee by helping his new side qualify for the group stages.
The 25-year-old was on target in his maiden outing last month, a 2-1 friendly victory over Al Batin, and he opened the scoring at Shanghai Stadium on Tuesday.
Odil Akhmedov surged forward on the break and picked out Oscar, who guided a cool finish into the bottom-left corner from the right-hand side of the box in the 34th minute.
Andre Villas-Boas' team doubled their advantage before half-time. Wu Lei was unable to get a shot away from Hulk's cross, but the loose ball was brilliantly back-heeled home by Elkeson.
Elkeson was denied a sensational second after the restart when his mid-air flick was batted away by Pairot Eiam-mak in the Sukhothai goal, while Oscar's rabona chip moments later crossed the line but was ruled out for a foul on the keeper.
Shanghai got their third when, after seeing a header tipped over the bar, Elkeson's dragged shot was turned into the net by Sukhothai defender Kiattisak Toopkhuntod.
Oscar was replaced by Yu Hai 10 minutes from time and with victory secured, Villas-Boas' side join FC Seoul, Urawa Red Diamonds and Western Sydney Wanderers in Group F.