photo finish
noun /ˌfəʊtəʊ ˈfɪnɪʃ/
/ˌfəʊtəʊ ˈfɪnɪʃ/
[usually singular]- the end of a race in which the leading runners or horses are so close together that only a photograph of them passing the finishing line can show which is the winner
- It was a photo finish, with three horses neck and neck at the finishing line.
- The race ended in a photo finish.