Current and former world champions Freya Colbert and Matt Richards secured their places at the Paris Olympics by winning British titles in London.
Colbert backed up world gold by winning the 400m medley and achieved the Olympic qualification time.
Richards won a stacked men’s 100m freestyle final with 200m Olympic champion Tom Dean missing out and Scotland’s Duncan Scott taking silver.
“That race was just as high pressure as an Olympic final,” Richards said.
“I thought I was capable of a bit quicker – maybe it wasn’t the best executed race but I can’t complain.
“I got the job done and have left plenty in the tank for the summer.”
Richards, the 2023 200m freestyle world champion, Dean and Scott, the Olympic silver medallist from the 200m freestyle, were all under the Olympic qualification time but with only two spots available for the Olympics per event, Richards took the automatic place and Scott is in prime position for the second.
The trio will all compete again in Sunday’s 200m freestyle – a race which could be even more hotly contested – while Dean and Scott have further chances to qualify individually for Paris in the 200m medley on Friday.
Alex Cohoon’s time in fourth was enough to secure him a place at a first Olympics as part of the 4x100m relay squad, along with Richards, Scott and Dean.
Colbert had already won the 200m freestyle British title this week but had said she was unlikely to race that event in Paris because of a clash with her main event, the 400m medley.
Her and Katie Shanahan were a class above the field in the final with Scot Shanahan also under the qualification time and likely to take the second Olympic place.
No British woman has won an individual Olympic swimming title since Rebecca Adlington in 2008 but Colbert, who won in a personal best time of four minutes 34.01 seconds, played down her chances of ending the wait.
In Paris she will likely race Canadian world record holder, 17-year-old Summer McIntosh, who was absent from this year’s worlds.
“McIntosh is head and shoulders above the rest,” Colbert said.
“I am not going to be saying I am going to do it. I don’t know if this will be the time.
“I would love it to be but I am also very realistic. I know what the rest of the field looks like.”