The judges called the work "the vital, energy-driven... with a clear and fearless voice, a voice that is often passionate and sometimes angry, but always lucid and warmly human."
The Arab-Australian poet and writer thanked all his readers on Twitter, after the award was announced via livestream.
"Holy holy. Oh my god. Alhumdulillah alhumdulillah alhumdulillah. My battery is on 1%. I haven't slept in two days so I forgot my charger. My beloveds, all of you, I wouldn't be here without you. Thank you thank you thank you," he wrote.
Earlier, Sakr wrote about the challenges of being a working class writer of colour, and how life-changing the $80,000 prize money would be in helping family.
"I know I'm supposed to pretend this is just another day, another ceremony, whatever. I can't. This would change my life forever. And I know the award system is so deeply flawed, and winning or losing awards is no reflection on the value of my work. It's not about that," he wrote.
"Something I thought genuinely beyond me. Now, maybe, possible. And with it I could stop worrying about my mum, who was homeless years ago, and had to crash at my sharehouse. Who I always fear will be homeless again soon. I'd be able to relax, finally. Knowing I could care for her."
The fiction prize went to Tara June Winch, for her book The Yield. Winch also won this year's Miles Franklin award and the Stella Prize for the novel. It features protagonist August Goondiwindi, who returns to her home country for her grandfather’s burial, only to learn the family's home will be taken over by a mining company.
