The Mexican director beat fellow awards season favourites, including Richard Linklater (Boyhood) and Wes Anderson (The Grand Budapest Hotel), to claim the title of Outstanding Directorial Achievement in Feature Film at the Los Angeles ceremony.
The big win cements Inarritu's position as a frontrunner to score gold at the Academy Awards, as the Dga champ typically goes on to repeat their success at the Oscars, as Gravity director Alfonso Cuaron did last year (14) after being feted by the Dga.
Meanwhile, it was ladies' night for the victors in the Tv categories - Jill Soloway was praised for her work on comedy series Transparent, Lesli Linka Glatter celebrated with the award for dramatic series for Homeland, Lisa Cholodenko's Olive Kitteridge landed her the movies for television and mini-series prize and Laura Poitras walked away with the best documentary honour for Citzenfour.
The Oscars will take place on 22 February (15), when Birdman will compete for nine awards, including Best Director, Best Actor for Michael Keaton and the coveted Best Picture.
Variety: DGA Awards Winners 2015 | Variety