:up: 'Pitch' can also be used to mean the space where a temporary trader or busker operates - so 'You're on my pitch' could also used without reference to any kind of sport.
But 'on the pitch' isn't idiomatic (in any context I've met). Rather than 'on the pitch' people use another idiom - also related to sport - "in play"; and if a situation is developing, you can say '[we won't know] until all the balls are in play' (a bit of a strange idiom, now I think of it, as most games I can think of with several balls - notably snooker and pool - start with all their balls in play and the number of balls in play reduces). Hmm...
b