Ronan Wantenaar excelled on the first day of the Fina Junior World Championships at Budapest, Hungary on Tuesday when he broke four Namibian records during his heats.
In the men's 100m backstroke event he won his heat in a time of 57,75 seconds which was more than two seconds faster than his own national 17-18 year age group and Open record of 59,91 seconds.
That time saw him finishing 37th overall out of 85 swimmers who completed the heats.
Thomas Ceccon of Italy had the fastest heat time of 54,07 seconds, followed by Will Grant of the United States (54,39) and Wyatt Davis of the United States (54,56).
In the 100m breaststroke Wantenaar once again won his heat, breaking two Namibian records with a time of 1:03,75.
He broke his own 17-18 year age group record as well as the Namibian Open record of Jorg Lindemeier of 1:04,60.
Kevin Houseman of the United States had the fastest heat time of 1:00,52, followed by compatriot Josh Matheny (1:00,66) and Archie Goodburn of Great Britain (1:01,01).
On Wednesday, Wantenaar competed in the men's 200m individual medley and once again set a new Namibian record when he finished third in his heat in a time of 2:07,47, beating his own former time of 2:08,04.
That was the 29th fastest time of 65 swimmers that completed the heats.
Carson Foster of the United States had the fastest heat time of 1:59,30, followed by Apostolos Papastamos of Greece (2:00,43) and Se-Bom Lee of Australia (2:00,54).