Anthony Charles Dobson was supposed to support his brother on his big day, but before the clock struck 10pm he was allegedly lunging at the barman with a broken wine glass.
Dobson, 35, was a groomsman for his brother's wedding at the upmarket Bridgewater Country Estate in Helensville, north of Auckland.
Part of a groomsman's duties are to support the groom, advise him and listen to any pre-wedding nervousness.
But police were called when Dobson allegedly became enraged after being refused alcohol by the bartender, who suspected he was drunk.
Constable Peter Collins was among the officers who arrived at the venue shortly after 9.30pm.