South Africa's Chad le Clos and Hungary's Laszlo Cseh have comfortably made it through to tomorrow's 100m butterfly final at the World Championships in Kazan.
Le Clos, who is the defending champion in this event, had a strong final 50m in the first semi-final to touch the wall second in 51.11s.
Cseh swam sub-51 in the heats this morning, but he was unable to match that by topping the race 51.03s.
The 29-year-old qualified fastest in the field alongside the USA's Tom Shields, while Le Clos clocked the third-fastest time.
