A neighbouring cat keeps entering our garden and attacking my cat !

Tipsy is a spayed female. I'm not sure whether this cat is male or female but it doesn't spray.

Other cats come and go and don't bother Tipsy at all but this cat has attacked Tipsy a number of times.

The visiting cat is quite sweet with humans - he's not afraid of me at all !!
But has an issue with my cat !

Twice today I had to spray water at him, the second time he had attacked Tipsy!


Any advice ?

Thanks !!