After the former Chelsea midfielder appeared to fire the ball deliberately twice at Guangzhou players, he was rushed by several opponents.
After the former Chelsea midfielder appeared to fire the ball deliberately twice at Guangzhou players, he was rushed by several opponents, fell to the ground and a melee broke out.
One player from each side was sent off as the opening of the CSL transfer window was marked in rambunctious style.
The fight erupted just before half-time in Sunday's CSL clash at Guangzhou R&F, where Andre Villas-Boas's SIPG were attempting to keep up the pressure on league leaders Guangzhou Evergrande.
Oscar, who cost SIPG a whopping 60 million euros ($67 million) in the last transfer window to become the biggest transfer in Asian football history, sparked the confrontation when he deliberately lashed the ball twice at R&F players.
The home side's Chen Zhizhao retaliated, pushing the 25-year-old Brazilian to the floor, then players, coaching staff and substitutes poured off the benches and waded in as Oscar lay face down on the pitch.
When order was restored after pushing and shoving, R&F's Li Tixiang and Shanghai's Fu Huan were dismissed and three others were booked.
Oscar was unhurt and the fiery encounter finished 1-1 to leave SIPG four points behind reigning champions Guangzhou Evergrande.
Portuguese manager Villas-Boas defended Oscar, saying that he was "just being passionate".
Another Brazilian international, the forward Hulk, equalised for Shanghai after being set up by Oscar just before the fisticuffs.
R&F players were incensed that the goal was allowed to stand as Oscar appeared to have been offside before his assist.
Villas-Boas told Shanghai's official social media: "Our goal should be offside and it was unlucky for Guangzhou."
R&F apologised after the home side racked up five yellow cards in addition to the one red.
"We are sorry about the infringements during the game and hope the players can adjust their attitude and prepare for the following game," R&F said in a statement.
But that apology might not be enough for the CSL and image-conscious Chinese Football Association (CFA).
Shanghai Shenhua's Qin Sheng was hit with a six-month ban earlier this year for stomping on Belgian international Axel Witsel of Tianjin Quanjian.
Then last month Zhang Jian, senior vice-president and general secretary of the CFA, called for "good order" between the league's foreign stars and domestic players after allegations of racism and a number of on-field flare-ups.