On paper this looked a tough ask for Ao, a former title holder at both Featherweight and Super Featherweight, though it probably became even harder last night after Beltran failed to make weight for the contest.
On the scales Ao was comfortably inside the limit weight in at 134¾lbs on his first show. Beltran on the other hand was 136lbs, a full 1lb over the limit, on his first attempt whilst an hour later he was 135½lbs, still over the limit.
As a result of Beltran missing weight Ao is the only man capable of winning the title. If Ao fails to win the bout the belt will remain vacant with Britain's unbeaten Terry Flanagan (27-0, 10) expected to fight for it next.
Ao looks to become a 3-weight world champion as he takes on tough guy Beltran (Preview)
(Image courtesy of Naoki Fukuda)