Rebecca Redfern and Aaron Moores both set new world records on their way to reaching their Rio qualifying standard on the opening day of the British Paralympic swimming trials in Glasgow.
Worcester's Redfern, 16, achieved the mark in the SB13 100m breaststroke, finishing in one minute 16.86 seconds.
Moores, who has learning disabilities, broke the SB14 world record of 1:06.69 with a 1:06.49 in the morning heats.
The 21-year-old from Trowbridge improved to 1:06.33 in the final.
"Coming here I wanted to get a personal best and the Rio qualifying time," the London 2012 S14 100m backstroke silver medallist told BBC Sport afterwards.
"But it's an amazing feeling to come away with two world records and it has boosted my confidence so much."
The pair were among 11 swimmers to beat the required qualifying standard on the first of five days of competition.
Redfern rises to the occasion
Redfern, who is visually impaired, could only manage 1:20.81 in the morning heats, leaving her with a big gap to make up in the final.
But the talented teenager, who will be making her international debut at next week's IPC Swimming European Championships in Madeira, was in superb form in the final.
"I really didn't expect to make such a big drop in the times," she admitted. "I knew I was capable of it so I just went and gave it what I had."
Fellow breaststrokers Scott Quin (SB14), Bethany Firth (SB14), Harriet Lee (SB9), Claire Cashmore (SB8) and Charlotte Henshaw (SB6) also beat their Rio qualifying standards.
In the 100m freestyle, Hannah Russell (S12), Susie Rodgers (S7), Andrew Mullen (S5) and four-time Paralympic champion Ellie Simmonds (S6) also beat the times needed.
The five-day event is the only chance for British swimmers to book their places on the team for the Rio Paralympics.