Who would really win? A T-rex or a Spinosaurus?

In Jurassic Park 3 there was a fight between a T-rex and a Spinosaurus and the T-rex died. Comment what you think would've happened! Although there was a lot arguments about what should've happened in the movie I agree with it because it was only a juvenile (apperently) however I think the T-rex would died then and there leaving fatal injuries on the Spino's sail later killing it (which they couldn't have let happen because they needed one to survive) I know the same happened with the Carcharodontosaurus in Planet Dinosaur (the Carcharodontosaurus would've died then and there but left the Spino with fatal injuries) and the same with T-rex vs Carcharodontosaurus (the Carcharodontosaurus would've died then and there but left the T-rex with fatal injuries) so who would really win? I think the T-rex would die then and there but the Spino would have fatal injuries to it's sail. Please comment what you think, I've accepted that my favourite will die (if they both don't die I think the T-rex would win) so tell me if you agree or not!