Zou Shiming waited until his 30s to begin his professional boxing career, and he has been in a hurry ever since.

In just his seventh pro fight, China's double Olympic gold medalist will attempt to claim the IBF flyweight title belt this weekend.

Although Zou is an underdog in many boxing observers' minds when he meets Thailand's Amnat Ruenroeng on another big-money card in Macau, Zou and his promoters are eager to justify his enormous popularity with a championship.

Zou is still learning to fight like a professional under trainer Freddie Roach, who has attempted to rebuild Zou's slick amateur fighting style into a durable pro skill set. But with his 34th birthday looming later this month, Zou didn't want to wait any longer to test himself against the best.

"I am very calm, not nervous," Zou said through a translator in Los Angeles recently. "I have been prepared for this moment for a long time. I am focused on myself, on executing Freddie's game plan. I felt a lot more pressure when I was in the Olympics. This time, the pressure is on Ruenroeng."

Zou's success has been the main reason for the growing popularity of boxing in China. His fight at the Cotai Arena in the opulent Venetian Macau will be available to more than 1 billion potential viewers in a nation where the sport was banned until the 1980s.

Yet Zou (6-0, 1 KO) realizes he is in for easily the most difficult test of his short pro career, which has been meticulously curated by promoter Top Rank to keep its prize Chinese fighter on a smooth path to title contention.

Zou likely won't be able to beat the tough Ruenroeng (14-0, 5 KOs) if he reverts to his point-friendly amateur style with little power behind his quick punches. He must be physical, durable and tenacious to win a belt, and Zou insists he is ready to show everything he has learned in two years under Roach.

The process has been a bit slower than Top Rank might have hoped, and Zou has just one stoppage victory as a pro. Yet he appeared to make significant progress in his last fight, knocking down previously unbeaten Kwanpichit Onesongchaigym three times on the way to a blowout decision victory.

"I feel very confident with the professional fighting style now," Zou said. "In my last fight, which went 12 rounds, I really felt like a professional fighter. That was a turning point for me."

Zou beat Ruenroeng twice in three meetings during their lengthy amateur careers. Ruenroeng, who has impressive reach for a smaller fighter, also didn't turn pro until relatively late, coming back from stints in prison to win the vacant 112-pound title in January 2014.

If Zou is as prepared as he believes, the first Chinese boxer to win Olympic gold could become the second Chinese fighter to hold a world title. Xiong Zhao Zhong won a 105-pound title three years ago, but lost it in February 2014.

"I want to make my country proud and advance the sport of boxing throughout China," Zou said. "I am ready for my date with destiny."