By Zou Shiming

Chinese boxer Zou Shiming is happy to have made his country proud but is even more delighted to have fulfilled his promise to his 13-month-old son.

Zou defended his light flyweight Olympic championship by overcoming Thai Kaeo Pongprayoon in a close fight.

The victory wrapped up China's London campaign by delivering the last of its 38 gold medals on Saturday night.

Zou overcame a heel injury and middle age to retain the title he won in Beijing in 2008. He said his most powerful motivator was a promise he made to his boy.

"My boy was born just one month before the London Games' one-year countdown. He is an Olympic baby, and I told him I would fight for a gold as his first birthday gift," an emotional Zou said after beating Pongprayoon 13-10 in the 49kg final at London's ExCeL.

"I realized the commitment of a father to his son, and that's the most important reward for me," the 31-year-old said.

Right after stepping out of the ring, Zou rushed to his wife, who watched and chanted as he hugged his son on the tribune. He kissed his boy and flew the national flag to celebrate his victory.

Zou's second gold made him the first man to win three medals in the light flyweight. He took bronze at the 2004 Athens Games and is the oldest Olympic champion in that class.

"I am so excited to finally get here," he said.

"I've come a long way. And I just want to stay with my family now, especially my son. No one can separate us now."

Zou, who was about to retire from the sport after the Beijing Games due to injury and had left the ring for nearly two years, struggled to return. He barely saw his son since he started training in the national camp in Hainan province in January.

Zou was proud but conflicted when his son gripped a boxing glove, as well as pens, toys and books, at his 100-day-old party - a Chinese tradition that's believed to hint to a child's future.

"He showed an inborn interest in boxing so young," Zou said.

"I'm sort of happy but actually don't want him to become a boxer. But if he insists on boxing when growing up, I'll respect his wishes and pass along what I know to him."

Zou is called the "pirate fighter" because of his iconic counterattack routine that's infused with Chinese martial arts. He was viewed as losing his edge at last year's World Championships, even though he won his third amateur title there.

Zou vowed to succeed in London and modified his style to become more aggressive, which was difficult for him due to his age and injury.

Chinese Olympic boxing team leader Li Pin said after the final: "Boxing is already hard for a middle-aged man, especially one with an injured heel. We knew how tough it was for him. But he never thought of quitting and stuck to it with great faith."

Zou triumphed over a slew of good fighters at the Games, including opener rival Yosbany Weitia of Cuba and Irish favorite Paddy Barnes in the semifinals.

But he didn't expect the final would be so challenging. His Thai rival was overwhelmingly cheered on by the crowd, which booed every time Zou retreated.

Zou said attacking the Thai was too risky, as the Olympic bout was too short to make any mistakes.

"I was so eager for victory and felt so much pressure, but I had to be patient and cautious," Zou said.

"The fight had only three rounds (at three minutes each), and I couldn't afford to take any risk while attacking."

Zou denied all interview requests from the quarterfinal on so he could remain focused for the final.

He said he "wouldn't say (his) career is over", hinting that he aspires to become China's first professional boxer.

He first revealed that ambition after the 2010 Asian Games but said he won't rush into a decision.

"Yeah, I've seriously considered it," he said.

"But I just want to rest with my family right now," the Guizhou province native said.

"I have injuries and fatigue to recover from. Talking about boxing at all just annoys me right now. I'll decide after a while and won't end it here."

Zou's mother Song Yonghui, who initially disapproved him of switching from Wushu to boxing, also opposed him going pro. She said her son's body couldn't bear more injuries.

But Zou remains as strong-minded as when he chose the sport 15 years ago.

"I will see if I can," he said.

"If I tune up well and still have the same desire, I'll try to persuade her to let me go forward."