Alfonso Cuarón has won the best director award at the Baftas for his outer-space thriller Gravity.

This is the director's first Bafta in this category, although the gothic fantasy that he produced, Pan's Labyrinth, won the foreign language prize in 2007, and his films Y Tu Mamá También and Harry Potter and the Prisoner of Azkaban were both previously nominated.

He said disbelievingly: "I don't know if I can open my mouth" when receiving the award. "I consider myself a part of the British film industry," he added, highlighting his living in London for 13 years: "I guess I make a good case for curbing immigration." He saluted his son, Jonás, "my teacher in film, my master in life", his star Sandra Bullock "who is Gravity", and wryly highlighted the "upstairs downstairs distinctions" between technical and artistic workers in film. Cuarón dedicated his award to the "downstairs" technical workers who delivered the film's exceptional effects, which won their own category earlier in the evening.

He produced Gravity with his Harry Potter co-producer, David Heyman. The film stars Sandra Bullock and George Clooney as a pair of astronauts who become dangerously cast adrift when their space walk is plagued with satellite debris. It is nominated for 10 Oscars, tying for the most nominations with David O Russell's comedy-drama American Hustle.

Cuarón's task as director required him to not only convey the human terror the situation, but also create a realistic-looking depiction of the dynamics of outer space. He was aided in the latter by the London-based visual effects studio Framestore, which spent more than three years working on the special effects. Gravity is regarded as one of the finest deployments of 3D screening technology yet attempted.

• Interview: Cuaron on Gravity
• Xan Brooks is live-blogging the ceremony here