Yang was a reigning world champion, having won gold in vault at both the 2011 and 2013 World Championships in Tokyo and Antwerp respectively. However, at the 2014 World Championships in Nanning, China, he fell on both of his vaults—the first for which it was announced in Nanning that he was widely expected but failed to received naming credit for a brand new top then 6.4 difficulty vault, initially dubbed the Yang Hak Seon 2, or a straight Tsukahara with 3½ twist—failing to defend his title and finished in seventh place with a final average combined score of 14.416 after qualifying in first place. Without any worthy competition, Ri Se Gwang of North Korea won the gold medal with two top then 6.4 difficulty vaults that were both named after him, the Ri Se Gwang (full-twisting double Tsukahara) and Ri Se Gwang 2 (double front piked with ½ twist), and outscored Yang by exactly one full point (15.416). He was similarly unable to defend his Olympic title at the 2016 Summer Olympics in Rio de Janeiro due to injury. At the 2017 Artistic Gymnastics World Championships in Montreal, Canada, Yang had "qualified" (Q) in first place for the vault event final but pulled out after that because he had sustained a hamstring injury during qualifications. Unimpeded and with little resistance, Kenzo Shirai of Japan won his world individual vault title with an averaged combined score of 14.900 ahead of vault's 2012 Olympic bronze medalist Ihor Radivilov of Ukraine by 0.001, the absolute slimmest of margins.