NANNING (AFP) - North Korean veteran Ri Se Gwang won his first global title on Sunday in the men's vault, as South Korea's defending champion and Olympic gold medallist Yang Hak Seon fell on landing twice.

His triumph followed his compatriot Hong Un Jong's victory in the women's vault on Saturday at the world championships in Nanning, China.

American teenager Simone Biles won her second gold of the championships on the women's balance beam, 0.067 of a point ahead of China's Bai Yawen. Biles had already successfully defended her all-around title on Friday at the Guangxi Gymnasium.

The 29-year-old Ri, who grabbed the 2007 world vault bronze and the Asian Games title in the event in 2006, displayed two technically demanding vaults to collect 15.416 points.

"I am very happy and satisfied with my performance today," Ri said and expressed sympathy for his South Korean rival.

"Mistakes are inevitable in athletic competitions," he said. "Actually (Yang) had a injury, so his performance was not so good. I hope he will recover soon and be better."

Ukrainian Igor Radivilov finished second on 15.333 and Jacob Dalton of the United States third on 15.199.

After Ri landed his second vault, he limped away having seemingly hurt his left foot but said: "There is nothing serious right now. I have already received some medical attention."

Yang, 21, the 2012 Olympic vault champion and double world champion in 2011 and 2013, fell onto his backside after back somersaults on both his vault attempts and finished fifth on 14.416.

London Olympic silver medallist Denis Abliazin of Russia fell and stumbled on his two vaults to finish bottom of the eight-man field on 14.116.