Mereshko proved too strong for the rest of the field in the S6 50m freestyle with a time of 34.14 sec .
Mereshko became the first swimmer to beat Great Britain 's Ellie Simmonds in the S6 400 metres freestyle for seven years on the opening day .
Mereshko , who became the first swimmer to beat Great Britain 's Ellie Simmonds in the S6 400 metres freestyle for seven years on the opening day , proved too strong for the rest of the field in the S6 50m freestyle with a time of 34.14 sec .