It's on Sport1, from 22:00 to midnight according to their schedule:
http://mediencenter.sport1.de/de/tv_...01201282300,04 . Sport1 has Braehmer topping the bill, but then they also seem to think Boystov & Chagaev are facing each other...
Here's the official fight poster:
...Boystov somehow reminds me of another legendary fight poster:
