Police have warned revellers against "pre-loading" - getting drunk before going out - saying they will be turned away from events if they are under the influence.
The warning came after two 19-year-old women ended up in the cells because they were too drunk to get into the races in Hawkes Bay last weekend.
Senior Sergeant Freddy van Duuren said the women and two male friends tried to get into the racecourse when it opened at 11am but were denied entry because they were "very, very drunk".
Their male friends disowned them so the women, who could barely stand, were taken to the Hastings station for detox.
It was not known what time the girls had started drinking, but it was likely to have been early, Mr van Duuren said.