Jaws dropped, but Venezuelan national pride soared, as a low-profile film from an unknown first-time director scooped the Venice film festival’s top prize the Golden Lion. Lorenzo Vigas’s film From Afar (Desde Allá) wasn’t considered by many as a front runner in a competition that included works from such high-profile names as Charlie Kaufman, Tom Hooper, performer turned director Laurie Anderson and 2011 Golden Lion winner Alexander Sokurov. But Vigas’s dark drama, about the relationship between a middle-aged gay man and a violent young street tough, was certainly one of the discoveries of the festival, and had plenty to recommend it – not least an audaciously minimalist performance from Alfredo Castro, the Chilean actor who in the last few years has become a cult star for his chilling presence in the films of director Pablo Larrain (notably Post Mortem and Tony Manero).

In From Afar - the first Venezuelan film ever to play in competition here - Castro plays Armando, a solitary dental technician who cruises the streets of Caracas offering money to young men to undress for him. He seems to have come a cropper when he runs into aggressive Elder – striking young newcomer Luis Silva – but the two form an unlikely rapport, although their relationship leads the story towards very sombre corners and a laconically troubling ending. Despite general admiration, Vigas didn’t entirely win over critics: many felt that the film’s moody visual style was too close to that of Chile’s Larrain, and indeed they share a cinematographer, Sergio Armstrong. From Afar certainly has some clout – the producers include Mexican novelist and screenwriter Guillermo Arriaga (21 Grams, Amores Perros), who co-wrote the story on which the film was based. And Far Afar was certainly a cinephile choice from a jury heavy with auteurs known for their seriousness – including president Alfonso Cuaron, Pawel Pawlikowski, Lynne Ramsay, Taiwan’s Hou Hsiao-hsien and Turkey’s Nuri Bilge Ceylan.

Extraordinary ... Anomalisa. Photograph: PR

Many bets were placed on the Golden Lion going to Anomalisa, the extraordinary stop-motion animation directed by Charlie Kaufman and Duke Johnson, but instead it took the Grand Jury Prize – although it was by far the most innovative and artistically haunting film of the festival. And I’d have loved to have seen some recognition for Laurie Anderson’s very idiosyncratic Heart of a Dog, a poetic essay film that was one of the most personal things on show here.

Other prizes were equally mysterious. The Silver Bear for Best Direction went to Argentinian stalwart Pablo Trapero for El Clan, a true-crime thriller about a family who run a kidnapping racket: an efficiently nerve-racking piece, but not the best from this respected realist director.

Then there was the prize for best female performance, for which favourites included Tilda Swinton, Juliette Binoche or (my own, admittedly left-field bet) Jennifer Jason Leigh for her voice-only role in Anomalisa: instead, the winner was Italy’s Valeria Golino. As for the male award, while Eddie Redmayne in The Danish Girl will certainly have his spotlight at more mainstream awards event, and Ralph Fiennes was a popular choice for his boisterous Brit in Luca Guadagnino’s A Bigger Splash, it seemed a slightly safe option to go for much-loved French star Fabrice Luchini, as a curmudgeonly judge in L’Hermine, which also won its director Christian Vincent the best screenplay prize.

No one, however, could have had qualms about the best newcomer acting prize that went to Abraham Attah. He is the 14-year-old street vendor from Ghana chosen to play an 11-year-old boy soldier opposite Idris Elba in Beasts of No Nation, the much-applauded Netflix-produced drama about war in Africa, directed by Cary Fukunaga (Sin Nombre, TV’s True Detective).

Perhaps the evening’s biggest surprise, though, was the double success of a film that rubbed many critics up the wrong way. The Childhood of a Leader was a sombre, sometimes mystifying French-set drama based on a Jean-Paul Sartre story, and starring Robert Pattinson and Bérénice Béjo. Guy Lodge in Variety called it “a overweening, maddening but not inconsiderable directorial debut”, but the film won two awards in the Orizzonti section, the Lion of the Future and the Special Orizzonti prize. The director and co-writer is Brady Corbet, a young American actor who has made a career in European art cinema, working with directors such as Olivier Assayas, Michael Haneke and Lars von Trier. Corbet’s was the only film screened in Venice on 35mm, and he said that using the medium “should be a film-maker’s right, not a privilege”. His film – with its hyper-intense string score by pop star turned avant-gardist Scott Walker – may not have pleased everyone, but Corbet offered the sound-bite of the night with his message to his young daughter: “Be patient, be radical, be free.”