South Africa's Chad le Clos was delighted to claim his second gold in Saturday's 100m butterfly final, but there was disappointment for birthday boy Ryan Lochte at swimming's world championships.

The 21-year-old le Clos, the Olympic and world 200m champion, clocked 51.06 sec, with Hungary's Laszlo Cseh at 0.39 back and Poland's Konrad Czerniak 0.40 adrift in the 100m final.

But Lochte, who has won three golds in Barcelona, finished sixth on his 29th birthday.