Great Britain secured three medals on day two of the second Youth Olympic Games in Nanjing.
"Initially the results board displayed that Dan had won but after the photo finish was reviewed my name came up," said the 15-year-old. "I gave it everything and I am so glad I managed to win gold – I am over the moon.
"The race is never over until the line; if I had stopped pushing five metres earlier then the gold medal wouldn't have been mine, so I just had to push all the way to the line."
The other two medals came in the pool, with Jessica Fullalove, 18, winning individual 100m backstroke silver before helping the 4x100m medley women team to another silver behind hosts China.