William Fox-Pitt has taken the individual lead in the eventing dressage at Rio 2016, just 10 months after being placed in an induced coma following a fall.
The 47-year-old Great Britain competitor suffered a head trauma in a cross-country fall last October and only returned to action in April.
Despite the incident, Fox-Pitt led with a dressage score of 37.0 penalties after the opening day at the Olympics in Rio on his 2015 Badminton Horse Trials winner, Chilli Morning.
Fox-Pitt told BBC Sport: "I'm lucky to be here. It was very special riding into the arena today. This is my fifth Olympics, they've all been useless! It would be great if this one went well."
Britain lie third behind Germany and Australia in the team competition.