Once my neighborhood was infested with stray cats. Many of them were un-neutered mangy ass tom cats who wanted nothing more than to take a piece out of my neutered cat. There is always the risk that they'll spread feline leukemia to your pet -so these cats were a disgusting menace.
I had the benefit of being in school -thus home all day. You may not have this ability. Also you don't seem to have the ability to sneak up on it. I suggest taking an alternate door and coming up from behind.
One day I found a stray trying to beat up my cat -who was sleeping peacefully. The stray was so fixated on jumping my cat that he didn't see that I was right behind it. I grabbed it by the back of the neck. I then unhooked it's claws from my pet -who seemed in shock from waking up. This was not easy -as the stray was clawing at my arms. I just grabbed the tuft of fur behind his neck
harder and eventually it was unhooked from my cat. It waving it's claws frantically and tried to flop out of my grasp. I just pinched it harder and held it away from my body.
I then took it up the alley and dropped it in a metal trash dumpster. It must have gotten out because weeks later I saw it running away from my cat. I guess my point is that if you teach this cat a lesson-he will eventually leave you alone. What I REALLY should have done was take the cat to animal control and had it neutered. However when you are dealing with a clawing spitting animal -you pretty much want to get rid of it asap.
Try a
havahart trap with some cat toy or something that smells like your cat. (Remember curiosity and cats -right?) Then when you do have this animal -check if he's neutered. If not -have him denutted and release him back into the wild. Problem solved... Otherwise -torture the beast a little in the area that he is not supposed to go in. Use the vinegar/water treatment.
And remember all of these treatments are better off than if animal control got involved. If you catch the animal and bring him there -chances are that his owner will never come get him.