As a small child in around 1970-72 I went to the cinema with my mother
in the UK and all I can remember about the film was two guys having a
fight in a house that was on fire. Anyone any ideas what it was called
- been bugging me for years!

I cannot offer an answer, but maybe some consolation. I had the same
thing happen to me until I saw the movie on TV (thirty years later)
and recognized the images (scary) from the time we visited the cinema
when I was a child.