Nadia Comăneci, in gymnastics
Comaneci scored a perfect 10 in her routine on the uneven bars, however the scoreboard was not set up to record a perfect 10 and displayed it instead as 1.00. Comaneci went on to score 6 more perfect 10s during the Games. She was 14 at the time. She also scored two perfect 10s at the 1980 Olympics but by then the technology had caught up.