Ex-NRL playmaker Junior Amone has failed to overturn his conviction for a rooftop hammer attack that saw his St George Illawarra contract torn up.

Amone, 22, appeared in Sydney's Downing Centre District Court on Friday where a judge dismissed his appeal against his conviction relating to a heated incident outside his family's Warrawong home in November 2022.

Junior Amone and his father, Talatau Amone, were in October last year both found guilty of a string of charges including assault occasioning bodily harm.

Magistrate Gabriel Fleming found the pair guilty of all charges after the court was told tradesmen Jai King and Dean West were working on a house opposite the Amone home when they became embroiled in an argument with a group of men over a Nissan Navara parked on a nature strip.

The magistrate found that Junior Amone then jumped on the top of the vehicle, while his father abused and threatened the tradesmen.

Ms Fleming found Junior Amone then climbed onto the roof of the property, where the men were working, while wielding a hammer.

Mr King jumped to a neighbouring roof to escape, falling and hitting an airconditioning unit on the way down, suffering serious injuries, including a broken hand.

The magistrate found evidence tied Junior Amone to the scene - including fingerprints on the windshield - and she was satisfied beyond a reasonable doubt that he was the man who chased Mr King from the rooftop.

He was found guilty of damaging property, intimidation and assault occasioning actual bodily harm and sentenced to a two year Intensive Corrections Order

On Friday, Judge William Fitzsimmons dismissed his appeal against his conviction and confirmed his convictions.

Mr Amone's Dragons contract was torn up in the aftermath of his conviction in October last year after he was deregistered.

Steve Zemek - NCA NewsWire