The time was a quarter of a second inside the mark she set just seven months ago as the teenager maintained her astonishing progress. Just 15 months ago Jackson was virtually unknown outside her home area. Since then she has demolished the national senior and junior records for the 50m butterfly and the junior marks for the 100m butterfly plus the 50, 100 and 200m freestyle to impress her senior rivals.
Meanwhile, Lauren Greenshields, the 16-year-old from Peebles, lowered the eight-year-old Scottish junior record for the 200m breaststroke. A time of 2min 38.60sec shaved 100th off the record held by Caroline Kerr and put Greenshields into last night's final as the fourth fastest qualifier behind Emma Dutton of Leeds.
Mark Foster, the world short course champion and record holder, joined the growing list of swimmers to withdraw from the championships due to illness. The flu bug first hit British swimmers at last week's European Short Course Championships in Lisbon and is continuing in Sheffield.