By Kieran Mulvaney

WASHINGTON (Reuters) - Two years ago, Victor Ortiz seemingly had the world at his feet, charming fans with a 1,000-watt smile outside the ring and electrifying them with his explosive fighting style between the ropes.

He was even dubbed boxing's new Oscar De La Hoya, who himself declared that, "Victor has the charisma, looks, smile and most importantly, he has the goods -- the talent -- to be the chosen one."

But all that came crashing down when he quit in the sixth round of a June 2009 fight where he was knocked down twice and badly hurt by Argentine opponent Marcos Maidana.

To boxing fans, turning away from combat is considered the ultimate sin, and many responded by turning away from him in droves.

But he also received expressions of support, including from American Floyd Mayweather Jr., who along with Filipino Manny Pacquiao is regarded as one of the best fighters in the world.

"He said: 'Look Vic, you're the one who's looked at as the next Oscar De La Hoya, the next Golden Boy. You lose, and what happens? The world forgets about you, right?'" Ortiz told Reuters. "He said, 'Keep in mind, you're going to be doing great things one day."

In April, after four unconvincing wins and a draw following his Maidana defeat, Ortiz squared off with WBC welterweight champion Andre Berto.

Each man visited the canvas twice during an enthralling battle but this time Ortiz kept going, dominating the second half of the fight to win a decision and take Berto's belt.

His reward was the ultimate boxing lottery ticket: a bout with the undefeated Mayweather at the MGM Grand in Las Vegas on September 17.

Mayweather and Ortiz will officially announce the contest at media conferences in New York and Los Angeles this week.

According to Ortiz (29-2-2, 22 KOs), the two years of negative reaction from fans never derailed him.

It is a resilience born from hardships encountered long before he became a boxer. His mother left the family home when he was seven years old and his father followed suit five years later.

At 15, he worked part-time to help older sister Carmen pay the bills and take care of them and their younger brother, Temo. When the Kansas native moved to southern California to pursue a boxing career, he took Temo with him and the two shared an apartment until returning home where he now runs a trucking business. The fraternal ties, however, remain strong.

"I help him out with his company, in terms of buying his truck parts or whatever else he needs sometimes ... because I'm his big brother and I think it's the right thing to do," said Ortiz. "He's the only thing I have in this life, you know?"

Ortiz now also has vindication, and an opportunity to complete a dramatic career turnaround by becoming the first man to defeat Mayweather. It is, he says, an opportunity he never expected, but one on which he plans to capitalize on.

"I'm a slumdog, right? I'm a stray. I'm not supposed to be anywhere near a stage like this," said Ortiz. "But I refuse to believe that. I've made up my mind that I'm going to be one of the all-time greats and that's where it's at."

(Editing by Frank Pingue)