Ryan Coetzee and Rio Olympics finalist Brad Tandy, as well as the talented youngster Rebecca Meder, all dipped below the qualifying marks in their respective events at Friday's World Swimming Short-Course Championships (25m) at the Kings Park Aquatics Centre.
The 16-year-old Meder qualified for her first senior world championships when she posted a qualifying mark in the 200m individual medley in the morning heats.
She posted a time of 2:12.35 before winning the event during the evening finals clocking 2:12.71 to beat breaststroke specialist Tatjana Schoenmaker to the wall.
Schoenmaker finished second with 2:13.11 with Marlies Ross bagging bronze with 2:13.27.
Coetzee won the 50m butterfly with a time of 22.99 with Tandy touching second in 23.12. Doug Erasmus finished third in 23.60.
Olympic gold medallist Chad le Clos, who already qualified for the world championships in the 100m freestyle, also dipped below the qualifying mark in the 50m butterfly during the morning heats.
Zane Waddell, who already qualified in the men's 100m freestyle won the 100m backstroke final with a time of 51.63. He was followed by Jacques van Wyk (52.70) in second place and Leith Shankland (54.36).
Erin Gallagher, who already booked her place for the championships in the 100m freestyle, added the 50m butterfly to her repertoire.
She won the sprint event in 26.07 with Tayla Lovemore finishing behind her in 26.32. Emma Chelius bagged bronze, clocking 27.69.
Ayrton Sweeney won the men's 200m IM in 1:57.96 14 with Ruan Ras finishing second in 1:59 96 with Damian Mullen taking bronze in 2:00.08.
Qualifying Times, Day 2:
Chad le Clos - 100m freestyle (46.45), 50m butterfly (22.57)
Zane Waddell - 100m freestyle (47.54)
Ryan Coetzee - 50m butterfly - (22.99)
Brad Tandy - 50m butterfly - (23.12)
Tatjana Schoenmaker – 200m breaststroke (2:18.93
Emily Visagie - 200m breaststroke (2:23.03)
Erin Gallagher - 100m freestyle (53.34), 50m butterfly (26.07)
Rebecca Meder - 200m IM (2:12.35)