Great Britain's Adam Peaty won 50m breaststroke gold at the World Swimming Championships in Russia to become the first man to complete the 50m and 100m double.
Peaty, who set a new world record in the semi-final, beat South Africa's Van der Burgh by 0.15 seconds, with American Kevin Cordes third.
The 20-year-old then helped GB win mixed 4x100m medley relay gold in a world record time in Kazan.
Chris Walker-Hebborn, Peaty, Siobhan-Marie O'Connor and Fran Halsall triumphed in three minutes 41.71 seconds.
The two golds, added with the five medals already won by British swimmers, puts Great Britain at the top of current medal table.