Both Chad le Clos and Ethan du Preez produced Olympic qualifying times at the SA Aquatic Championships on Thursday at the Newton Park Swimming Pool in Gqeberha.
Le Clos won the 200m butterfly final, setting a time of 1:55.88, with Du Preez second in 1:56.44.
Ross Hartigan was third, stopping the clock in a time of 2:01.73.
“For me personally, I am very happy, 1:55 is right on my best for nationals," said Le Clos after the race.
“I am not really at the peak of my work but I take every race very seriously and focus really hard, so I am just excited to be back on a good time,” he added.
17-year old Matt Sates won the men's 100m freestyle final in a time of 49.29.
Matthew Bosch and Douglas Erasmus finished second and third respectively.
The championships will run till Monday.