Holy ****, the Pogues wrote a song about boxing? This is a rare overlap of interests for me. The warriors code by Dropkick Murphys has Mickey Ward on the cover and the title track is dedicated to him.
Sun Kil Moon have done a few. Mark Kozelek (their vocalist and guitarist) is a big boxing fan. 'Salvador Sanchez' is one of their best songs.
Oddly enough, Phillip Anselmo of Pantera, a huge boxing fan who has written online articles about the sport, has never done a song about it. Pity.
Without question the two best are: Stand and fight - Nigel Benn, https://www.youtube.com/watch?v=Y4Ic6k3iuMQ Y'all musta forgot - Roy Jones Jr, https://www.youtube.com/watch?v=pWIqZKhNY90 "I'm the warrior...that makes you sorrier".......pure poetry. Emotional.