Males fight for a pretty pinto mare as she escapes the immediate area for her safety. Shooting the action in 4K video, I watched through the viewfinder as these the stallions engaged in an intense fight for a several minutes. The challenger seemed to be winning the battle toward the end, but both stallions had bloody wounds.
In this kind of all-out furious fighting, the males hold nothing back and would (and have) killed to take out the other horse. It is the instinctively learned skills the males have practiced in youthful play and later when two bachelors hone their skills as they get the nerve to challenge an established stallion for his first female.
This image was one frame from the 4K video. I love the 4K video feature that allows me to get 8MP images from each frame.