Great Britain's Bethany Firth and Alice Tai set new world records on the penultimate day of the British Para-Swimming International meet in Sheffield.
Firth, who claimed three Paralympic golds at Rio 2016, lowered the S14 world record by clocking a time of one minutes 04.62 seconds in the 100m butterfly.
Rio bronze-medallist Tai broke the S9 100m backstroke world record as she registered a time of 1min 07.66secs while winning her event.
Tai, quoted by British Swimming, said: "It's seems so surreal right now to be a world record holder.
"Going into the race my PB was 1min 08.34secs so I was going to be happy with anything close to that.
"I've not been close to my PB in a while so to go a 1:07 and knock lots of time off my PB and get the world record is just crazy."
Britain's Paralympic champion Ellie Robinson (S6) won the 50m butterfly event, while there were new British records set by James Hollis (S10) in the 100m butterfly and Stephen Clegg (S12) in the 100m backstroke.
