Chris Eubank Sr. caused brain damage to Michael Watson during their 1991 world title fight. Watson suffered a near-fatal brain injury after Eubank delivered a devastating uppercut, which resulted in Watson spending a year in intensive care and being wheelchair-bound for six years. This injury effectively ended Watson's boxing career, and the severity of the injury and inadequate emergency response at the scene have been widely discussed. Eubank Sr. has been haunted by the incident, which left a lasting emotional scar on him.

Additionally, in 2016, Chris Eubank Jr. was involved in a fight with Nick Blackwell that resulted in Blackwell sustaining a skull bleed and being placed in a medically induced coma, though this was a separate incident involving Eubank Jr., not Eubank Sr..

Therefore, the individual who received the brain damage from Chris Eubank Sr. was Michael Watson.