The first person charged under the state's controversial "one-punch" laws for fatal alcohol or drug-fuelled assaults has been jailed for a maximum of 10 years, including a mandatory minimum of eight years, for the death of Sydney nurse Raynor Manalad.

Hugh Bacalla Garth, then 21, delivered a single, savage blow to the head of the 21-year-old nursing graduate outside a birthday party at Rooty Hill in western Sydney on May 2, 2014.

District Court Judge Antony Townsden said Mr Manalad, who had just started working as a registered nurse, "tragically never regained consciousness".

At the time of the offence, Garth was on a good behaviour bond for assault and breaching a domestic violence order, Judge Townsden said.