In terms of British heavyweight clashes it reminded me of the first war between Whyte and Chisora, two limited guys going at it and fighting to the point of exhaustion and fighting on will and instincts.
Best dust up since the last British domestic dust up between two Brits who one or more of hasn't been corrupted by studying or having graduated at the American school of slickness ie. like Viddal Riley vs Mikael Lawal. Fabio vs Frazer was epic but British domestic dust ups generally are. Hence why they're the envy of the boxing world and are must see TV.
In terms of HW fights, Whyte vs Chisora 1 like Brighton said. You could also add in Arreola vs Kownacki maybe, though that wasn't fought at the same intensity level because both fighters were slugs.