23-year-old Matthew Luke Sharman was already banned from entering licensed premises when he went into the Mulcaster Street bar on 5 February.
Later, it’s alleged that he committed a grave and criminal assault against another man, before resisting arrest.
He admitted all three charges in the Royal Court on Friday.
Jersey-born Sharman, who appeared in a loose grey t-shirt, was remanded on bail by Bailiff William Bailhache, presiding, who sat with Jurats Jerry Ramsden and Mike Liston MBE.
He will reappear for sentencing on Friday 30 June.
