Doha - South Africa's Chad le Clos has set a new world record of 48.44sec in the 100m butterfly at the World Short-Course Swimming Championships in Doha on Thursday.
The 22-year-old had already threatened the world record this season, just 0.08sec off Evgeny Korotyshkin's mark at the World Cup in Hong Kong in September.
Le Clos cut 0.04sec off Korotyshkin's record from November 2009 -- all the more impressive given that was during the performance-enhancing suit era.
This is Le Clos' second gold medal of the championships after winning the 200m men's freestyle final on Wednesday.
Meanwhile, Cameron van der Burgh was unable to finish on the podium in the 100m men's breaststroke, finishing in fourth.
The race was won by Brazil's Felipe Franca Silva in a time of 56.29sec, 0.06secs ahead of Britain's Adam Peaty and France's Giacomo Perez-Dortona in third.
In earlier action, the South African 4x50m men's medley relay team of Ricky Ellis, Giulio Zorzi, Clayton Jimmie and Luke Pendock have finished eighth in their final, while Sebastien Rosseau finished fourth in the 400m individual medley.
Results and podiums from the second day of the 2014 world short course championships in Doha on Thursday:
Men
4x50 medley
1. Brazil 1min 30.51sec World Record (previous record: 1:32.78 by Russia, December 4 2014 in Doha)
2. France 1:31.25 European Record
3. USA 1:31.83
400m individual medley
1. Daiya Seto (JPN) 3min 56.33sec
2. Kosuke Hagino (JPN) 4:01.17
3. David Verraszto (HUN) 4:01.82
100m backstroke
1. James Larkin Mitchell (AUS) 49.57sec
2. Radoslaw Kawecki (POL) 50.11
3. Ryosuke Irie (JPN) 50.12
100m breaststroke
1. Felipe Franca Silva (BRA) 56.29sec
2. Adam Peaty (GBR) 56.35
3. Giacomo Perez Dortona (FRA) 56.78
100m butterfly
1. Chad Le Clos (RSA) 48.44sec WR (previous record: 48.48 by Russian's Evgeny Korotyshkin, November 15, 2009 in Berlin)
2. Tom Shields (USA) 48.99
3. Tommosa d'Orsogna (AUS) 49.60
4x200m freestyle
1. USA 6min 51.68sec
2. Italy 6:51.80
3. Russia 6:51.96
Women
50m breaststroke
1. Ruta Meilutyte (LTU) 28.84sec
2. Alia Atkinson (JAM) 28.91
3. Moniek Nijhuis (NED) 29.64
100m backstroke
1. Katinka Hosszu (HUN) 55.03sec WR (previous record: 55.23 by Japan's Shiho Sakai, November 15, 2009 in Berlin)
2. Emily Seebohm (AUS) 55.31
3. Daryna Zevina (UKR) 55.54
800m freestyle
1. Mireia Belmonte (ESP) 8:03.41
2. Jaz Carlin (GBR) 8:08.16
3. Sharon van Rouwendaal (NED) 8:08.17
Mixed Relay
4x50m medley mixed
1. Brazil 1min 37.26sec
2. Great Britain 1:37.46
3. Italy 1:37.90