* Iran's acclaimed Farhadi seen as top prize front-runner
* Like "A Separation", "The Past" looks at family, divorce
* Only Chinese entry is thinly veiled political critique
Oscar-winning Iranian director Asghar Farhadi premiered his latest tightly wound family drama at Cannes on Friday, confirming critics' advance buzz it would prove a contender for the film festival's top prize.
The prestigious festival on the French Riviera - where the sun finally emerged on day three - is looking to spot its Palme d'Or winner among the 20 entries in the main competition and early reviews were enthusiastic for "Le Passe" ("The Past").
The intense psychological drama, shot in Paris in French, is Farhadi's first to be filmed outside his homeland, where Iranian censors have allowed the movie to be distributed.
"Le Passe" stars well-known Iranian actor Ali Mosaffa as an Iranian man who returns to Paris to finalise a divorce with his wife, Mariel, played by French actress Berenice Bejo ("The Artist").
Among the many warm reviews, The Guardian's Peter Bradshaw called the film: "A finely crafted, sinewy drama that anatomises clotted and complex relationships."
Back in his former home, "Ahmad" (Mosaffa) is thrust into a complex drama involving Mariel and her new partner, whose wife is in a coma, and a resentful teenage daughter struggling to come to terms with her own guilt.
"There is nothing more universal than family. That is a bond between my spectators and myself," Farhadi told reporters.
"The relationship ... between a couple is perhaps the oldest relationship in the history of humanity. There is so much suffering and pain linked to a couple, yet this suffering and pain is always different, unique."
Farhadi's last film, "A Separation", which also centred around a divorce, swept the awards circuit in Europe before winning an Oscar for best foreign language film last year, the first Iranian film to win an Academy Award.
In "Le Passe", Farhadi creates tension that does not let up from start to finish. Much of the drama takes place in enclosed spaces - whether inside a car, where accidents can occur at any moment, or a kitchen, where family secrets are revealed.
Asked about censorship by Iranian authorities, Farhadi told reporters that even more dangerous was self-censorship.
"I'm sure I have assimilated many of these restrictions, they are part of me. What I try to do is not to see this as a form of obstacle but as an asset. I try to find some source of creation in this kind of a situation."
Also premiering on Friday was "Tian Zhu Ding" ("A Touch of Sin") by director Jia Zhangke, China's sole entry for the top prize.
Whereas Farhadi's film steers clear of politics, Jia's look at China's confrontation with modernity points the finger at the authorities.
Jia said censorship was not an issue, as the film was based on real events widely covered in the Chinese press.
Coal miners fighting against regional corruption; migrant workers constantly on the move; abused prostitutes and suicides by frustrated assembly-line workers are all elements Zhangke weaves into a mosaic of contemporary life.
"No justice!" cries one of the characters in the film, when thwarted in his quest to stop regional bosses from bribe-taking.
Cities loom in the distance throughout Jia's film, with bulldozers and construction sites a constant reminder that urban sprawl continues, encroaching on the lives of the characters.
Jia's documentary "I Wish I Knew", about the development of modern Shanghai, competed in 2010 in Cannes' "Un Certain Regard" category for emerging directors.