The filmmaker snubbed an invite to attend the world premiere of his project at the prestigious Italian event, but his absence had little affect on the media's rousing reaction to the film, which is based on the hit Broadway play God of Carnage.
The big-screen adaptation stars Kate Winslet, Jodie Foster, John C. Reilly and Christoph Waltz as two sets of parents who meet up after their kids brawl at school - and their performances have been well-received by film critics.
The Hollywood Reporter's Todd McCarthy writes, "Roman Polanski's mastery of films within small spaces is evident in his adaptation of the Yasmina Reza play."
Meanwhile, a writer for Britain's The Telegraph newspaper brands Carnage "well-acted and giddily enjoyable", while the Associated Press reporter notes the comedy drew "rounds of applause and riotous laughter" at the early screening.
Winslet, Reilly and Waltz were all on hand to celebrate the big premiere on Thursday afternoon, while Polanski and Foster were notable absences.
Polanski's decision to stay away is said to stem from the legal battle which ensued after he was arrested at the Zurich Film Festival in Switzerland in 2009. He subsequently fought extradition to the U.S. to face court proceedings linked to a 1977 sex case.
Polanski was allowed to walk free following several months of jail time and house arrest at his Swiss chalet after the extradition bid fell apart.