According to Sports Navigator:
Hustle drew a 4.0% rating on TV-Tokyo.
K-1ís Dynamite event drew the following:
6:00-8:30 PM - 11.1%
8:30-11:00 PM - 14.7%
11:00-11:34 PM - 11.1%
In other words, not very strong across the board.
Kohaku (Red & White Music Festival) drew a 32.8% rating in part one and 39.5% rating in part two of their night-long show on NHK.