Chad le Clos and Cameron van der Burgh are set to dive into action at the world championships in Budapest today, carrying South Africa's medal hopes.
Van der Burgh pulled out of the 100m breaststroke heats on Sunday to boost his chances of reclaiming his 50m breaststroke crown from Englishman Adam Peaty, who won the 100m in a 57.47sec championship record last night.
Le Clos withdrew from the 200m freestyle heats yesterday morning to focus on his two butterfly races, starting with the 200m heats today.
The 2013 world champion is up against a tough field, including Hungary's reigning world titleholder Laszlo Cseh.
Myles Brown was the only South African swimmer in action last night, ending seventh in his 200m freestyle semifinal in 1min 47.19sec, missing out on a spot in tonight's final by less than a second.
Peaty had targeted his own world record of 57.13, set when he won the Olympic title last year in Rio de Janeiro, but came up short in his bid.
"I need to have a few more 57 lows to get down to 56, but I'm just going to follow that curve now and see where it goes," Peaty added.
Sweden's Sarah Sjostrom narrowly missed her own world record in becoming the first woman to win four golds in the women's 100m butterfly.
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