To the boxing ring, where Zou Shiming is looking to win the vacant WBO world flyweight title. The two-time Olympic gold medalist will face a familiar foe, Prasitsak Papoem of Thailand, Saturday in Las Vegas. The Chinese won their previous encounter in Macao in November 2014 by unanimous decision.

This rematch highlights the undercard of Manny Pacquiao's comeback fight against Jessie Vargas. And the two flyweights hope to steal the show, as they seek the elusive world title.

Zou is a two-time international flyweight champ, and defended the belt in his last fight in June. That was at Madison Square Garden in New York, where the Chinese claimed a unanimous decision over Hungarian teenager Jozsef Atjai.

Zou's clash with Papoem is his first world title shot since suffering the only loss of his pro career, versus Amnat Ruenroeng in March 2015. The Thai retained the IBF version of the belt in that bout.

The 35-year-old Guizhou native will be looking for his third straight win since his only professional setback.

But Papoem has also been on a roll since falling to Zou two years ago, stepping into the ring four times as often as the Chinese. The Thai will be seeking his 13th straight win.

The loss to Zou is the lone defeat of his pro career, so the former Olympian knows he will be out for revenge.

Zou said, "This opponent is the most dangerous one, even though I have already defeated him, because we know each other very well. Good strategy helped me win our previous fight in 2014. But this time, he will draw lessons from that bout, so I have trained very hard over the past three months."