Zou Shiming of China celebrates after his unanimous-decision victory over Prasitsak Phaprom of Thailand during their WBO flyweight championship fight at the Thomas & Mack Center in Las Vegas, Nevada, US, on Nov 5, 2016. [Photo/VCG]

Phaprom, 35, had scored 12 straight KOs since losing to Zou in Macao two years ago. He dropped to 39-2-2.

"He's dirty as hell," Roach said of the Thai when the rematch was announced.

"The last time we fought him, Prasitak was head-butting and landing low blows throughout the whole fight. I've warned my guy to be ready to respond this time."

There was no need.

Zou never gave Phaprom the opportunity to turn it into a street fight, keeping the pressure on the smaller man by stalking rather than chasing.

On the few occasions Phaprom was able to mount anything that resembled a sustained attack, Zou's slick footwork and lightning-quick jab got him out of trouble.

In round 6, Zou showboated by dropping his hands and sticking out his chin, daring Phaprom to try to hit him. In the 9th, he did a passable imitation of the Ali shuffle while the frustrated Thai threw punches at air.

Phaprom, who landed only 107 of 503 punches (21 percent), paid a heavy price for trying to get inside. Zou opened a cut over his left eye in round 5, and targeted it for the rest of the fight.

The victory was sweet redemption for Zou, who in his first crack at a world title was soundly beaten by then IBF champ Amnat Ruenroeng 20 months ago in Macao.

"Zou's success has gained the notice of a new fan base in the US, and he has become a big name in terms of sponsorships, ticket sales and Chinese TV revenue," Top Rank promoter Bob Arum said before the fight.

"I know (casino magnate) Steve Wynn is delighted to have Zou in Vegas because a lot of high-rollers from China are here to see him. And a win means huge fights for him in China in 2017."

murraygreig@chinadaily.com.cn