Complex sentence: At the pre-fight press conference in Doncaster both fighters squared up to each other and promised to knock each other out and during the highly charged face off both fighters had to be kept apart by their promoter and trainers.
Split into simpler sentences: At the pre-fight press conference in Doncaster both fighters squared up to each other and promised to knock each other out. In the highly charged face off both fighters had to be kept apart from each other by their promoter and trainers.