KAZAN, Russia (AP) — Adam Peaty of Britain has set a world record in the 50-meter breaststroke at the world swimming championships.

He won the first semifinal heat in 26.42 seconds, bettering the mark of 26.62 set by Cameron van der Burgh of South Africa in the morning preliminaries Tuesday.

It was the second men's world record to fall at the worlds after four women's marks were set in the first two days.

Peaty also swam 26.62 at the European Championships in Berlin last August but that mark was not approved by world governing body FINA because he wasn't tested for the blood-booster EPO.

The 50 breaststroke is not an Olympic event.