Volkswagen Golf R VS Focus RS
They seem to be the two main competitors, though when it comes to performance hot hatches there's quite a few on the market. Though nothing has been confirmed yet, the Golf R is expected to match the current Focus RS with 350 hp.
Numbers aside, the Focus RS sales has come to an end so it really won't be a competitor for the Golf R in sales until the next generation comes out and that won't be for a few years yet. Volkswagen just needs to take advantage of that window of opportunity.