Sates had been second in his heat behind Seto in 1:52.52, which was joint-fourth quickest overall, but he found that extra gear in the final.
“I don’t know what to say,” said Sates, whose previous personal best in this event was 1:51.45.
Veteran Chad Le Clos and schoolboy Pieter Coetzé both qualified for Wednesday finals.
Commonwealth Games champion Coetzé delivered two personal bests in the 100m backstroke on the day — 50.26 in the heats and then an impressive 49.85 continental mark in the semifinals, which was fast enough to place him only fifth in a race won by American star Ryan Murphy in 49.17.
The young South African was sixth-fastest overall.
Le Clos will be seeded fifth for Wednesday’s 50m butterfly final after finishing third in the second semifinal of the night. The 30-year-old clocked 22.09 behind Hungarian winner Szebasztian Szabo, the quickest of the night in 21.90.
In the morning heats the women’s 4x100m freestyle relay team of Milla Drakopoulos, Caitlin de Lange, Emily Visagie and Rebecca Meder combined to clock a 3min 41.57sec African record
Meder and Visagie also cracked personal bests in individual races, Meder going 2:07.47 in the 200m medley and Visagie 28.39 in the 50m butterfly.
Breaststroker Lara van Niekerk, the double Commonwealth Games gold medallist and the only South African swimmer to make a podium at the long-course world championships, rolls into action on Wednesday in the 100m breaststroke.
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Swimming
Matthew Sates lands South Africa’s first world title at Melbourne gala
Pieter Coetzé sets African record in 100m backstroke
The king has a crown at last. Matthew Sates, after an up and down 12 months, landed the first global title of his career when he won the 200m individual medley at the world short-course championships in Melbourne, Australia on Tuesday night.
Sates, the top male swimmer of the World Cup series last year, missed out on the 2021 edition of the championships because of Covid-19 travel restrictions.
He bounced back with an NCAA title at the US collegiate swimming finals, but then endured disappointing campaigns at the world long-course championships in Budapest and Commonwealth Games.
Sates even lost his World Cup title a few months back, but on Tuesday he delivered a fine performance as he downed a field that included defending champion Daiya Seto of Japan.
The 19-year-old Pietermaritzburg swimmer led after the opening butterfly leg and was third after the backstroke, the weakest of his four strokes. Then he powered back into the lead in the breaststroke and put the hammer down in the final two laps of freestyle to win in a 1min 50.15sec African record.
American Carson Foster was second in 1:50.96 and Finlay Knox of Canada third in 1:51.04.
Sates had been second in his heat behind Seto in 1:52.52, which was joint-fourth quickest overall, but he found that extra gear in the final.
“I don’t know what to say,” said Sates, whose previous personal best in this event was 1:51.45.
Veteran Chad Le Clos and schoolboy Pieter Coetzé both qualified for Wednesday finals.
Commonwealth Games champion Coetzé delivered two personal bests in the 100m backstroke on the day — 50.26 in the heats and then an impressive 49.85 continental mark in the semifinals, which was fast enough to place him only fifth in a race won by American star Ryan Murphy in 49.17.
The young South African was sixth-fastest overall.
Le Clos will be seeded fifth for Wednesday’s 50m butterfly final after finishing third in the second semifinal of the night. The 30-year-old clocked 22.09 behind Hungarian winner Szebasztian Szabo, the quickest of the night in 21.90.
In the morning heats the women’s 4x100m freestyle relay team of Milla Drakopoulos, Caitlin de Lange, Emily Visagie and Rebecca Meder combined to clock a 3min 41.57sec African record
Meder and Visagie also cracked personal bests in individual races, Meder going 2:07.47 in the 200m medley and Visagie 28.39 in the 50m butterfly.
Breaststroker Lara van Niekerk, the double Commonwealth Games gold medallist and the only South African swimmer to make a podium at the long-course world championships, rolls into action on Wednesday in the 100m breaststroke.
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