An unemployed man from western Sydney said he and his wife were at home on Thursday night discussing their plans for the future when he received a phone call that would change their lives.

A few days earlier, the man, in his 30s, had bought a ticket for Thursday night's Powerball draw online. It was the first time he had done so, and he hadn't seriously contemplated the possibility of winning.

A few minutes after Thursday night's Powerball draw, he answered his phone, only to be told that he was the sole division one winner. He had scooped the entire $50 million prize.

The man, who wished to remain anonymous, thought someone was having a laugh.