A Christchurch man caught masturbating at a girls' softball game has entered a guilty plea.

Thirty-five-year-old Martin Graham had been smoking cannabis before he went to Cowles Stadium last month.

The game involved girls aged between 13 and 17 and police say there were a lot of young children and families watching on.

Graham ran off but was later caught by police.

He's today pleaded guilty to committing an indecent act and possession of cannabis.

He's been remanded on bail to be sentenced on July the 12th.