U.S. Olympic boxer Demetrius Andrade works out in a training session last month in New York City.

AP / Mary Altaffer

Demetrius Andrade’s Olympic journey began 14 years ago.

He was 6 when he used to climb in the back of his father’s car with his older brother Mike, who was then the boxer in the family, and head to a karate studio that his father, Paul, opened with his good friend Joe Perez.

Their mission: to become the best boxers in the world.

It was there where Paul taught his two sons how to box, and it was there where Andrade first dreamed about fighting for the United States Olympic Boxing Team.

Back then it was just a fairy tale.

Today, in Beijing, China, that fairy tale comes true.

All of the hard work has paid off. All of the sacrifices he has made over the past 14 years have become worth it.

And perhaps the best news for United States boxing fans is that Andrade is predicted to win the gold.

The two-time national champion and two-time national Golden Gloves winner enters the 16-day competition as the reigning world champion in the 152-pound division, which makes him the top-ranked welterweight amateur boxer in the world.

Andrade, 20, an explosive and quick southpaw boxer who has excellent defense, will have the target on his back at the Olympics, but he said he’s not feeling any pressure.

“I’ve been dreaming of this moment for years,” said Andrade, who has been ranked as the top U.S. amateur welterweight for more than three years.

He said that the biggest honor for an amateur boxer is to fight for his country. Andrade is not just settling on making an appearance at the Olympics; he wants to win the gold medal for Providence, for the United States, and for his daughter, Autumn, of Providence, who turns 2 this month.

“To win gold it will take me being focused,” said Andrade, a 2006 graduate of the Providence Health Science and Technology Academy high school. “I have been working at this for a long time. All the work comes down to a month. It means the world to me to fight for USA. I love my country.”

Andrade’s plan is to set the tone in all of his fights, not leaving anything to chance.

“I’m going to walk these guys down and punish them,” Andrade said.

Andrade’s co-coach David Keefe said: “He just has to break people down, mentally, then physically. Once you break someone’s mind, the body follows, and he is real good at that. If he does what he is supposed to do, as he did in Chicago [at the World Championships], some of the fights won’t even be close and judging won’t be an issue.”

Andrade’s toughest competition at the Olympics will be Non Boonjumnong, of Thailand, whom Andrade beat in the finals at the World Championships, Bakhyt Sarsekbayev of Kazakhstan, Hanati Silamu of China, and Carlos Banteaux of Cuba.

It doesn’t matter to Andrade whether he gets a tough opponent in the first round, he said.

“It really makes no difference to me. I’m going to beat them all regardless of when I fight them,” Andrade said.

His coaches have the same confidence.

“Demetrius has never been a fast starter,” Keefe said. “I expect him to get sharper and sharper as the fights go on ... I want him to take it one at a time, and go out there and do what he has been trained to do. If he does this, he will win gold.”

Team USA boxing coach Dan Campbell recently said that he would be surprised if Andrade did not medal.

Andrade earned a place on Team USA’s boxing team after several dominating performances at last year’s Golden Gloves and U.S. Olympic Trials.

For the past 10 months, he has been living and training with the Olympic Boxing Team at the Olympic Training Center in Colorado Springs, Colo.

“He has worked incredibly hard,” Keefe said. “He has given up a lot for this. People don’t realize the sacrifice one makes. There is much more that goes on in this sport than just the fight.”

At the Olympic Trials, Andrade dominated all three of his opponents, stopping David Lopez in the quarterfinals and Charles Hatley in the semifinals before a convincing 21-13 victory over Keith Thurman in the finals to earn his spot on the Olympic team.

“He will be ready,” Keefe said. “He has a strong heart and unbelievable desire.”

Andrade said he wouldn’t be where he is today without the love and support of his family and friends, especially his dad and Keefe, who he said taught him right from wrong at an early age and emphasized getting a good education more than boxing. Andrade’s father will be in China watching his son’s matches.

Andrade has become a role model to other kids, and he has fans that he never expected, like New England Patriots coach Bill Belichick, who invited Andrade up to Foxboro for a visit last month.

“I went to meet Coach Belichick with a lawyer friend of ours, my dad and Dave,” Andrade said. “It was real interesting to meet the best coach in football. I told him if he needs a cornerback, I might be available.”

A dream fulfilled, Andrade begins his quest for an Olympic gold medal Sunday at the Workers’ Indoor Arena in Beijing. NBC has scheduled welterweight coverage from 4 to 7 p.m.

“Getting to the Olympics was hard,” Andrade said. “I had to leave my family and coaches for the better part of a year … but it will be worth it when I come home to Providence with a gold medal around my neck.”

roblee@projo.com