This is right up there with Luis Suarez taking a chunk of Giorgio Chiellini, except this hit was so dirty that Luiz Adriano is left completely knocked out.
The incident occurred during a Ukrainian Premier League match on Friday by Oleksandr Chyzhov. Surprisingly Chyzhov was only given a yellow card, even after Adriano was taken off the field on a stretcher.
[h/t Yahoo Sports]