A man accused of throwing a fatal punch at a western Sydney party will be the first person to be dealt with under the NSW government's one-punch laws after his charges were upgraded on Wednesday, a Sydney court has heard.

Nursing graduate Raynor Manalad, 21, died after he was allegedly punched on the head outside a birthday party at Rooty Hill in the early hours of Saturday.

Victim: Raynor Manalad on his graduation day. Credit:Facebook

Hugh Garth, 21, appeared briefly before Blacktown Local Court, where police laid two extra charges including assault causing death while intoxicated.

Under new laws introduced in January, anyone who fatally punches someone while intoxicated will receive a minimum eight-year jail term.