By Tim Arango

New York Times News Service

IMPERIAL, Calif. — Andy Ruiz Jr. is chubby, there is no getting around that.

He has been called a “fat slob,” the “Pillsbury Doughboy” or, more charitably, a “lunch-pail guy.” He has been compared, by a former trainer no less, to the cherubic and overweight boy Russell from the movie “Up.” His prefight ritual of scarfing down Snickers bars has only fed this image.

But now there is a new nickname, one his father shouted from the audience recently at the Jimmy Kimmel show in Los Angeles as the younger Andy Ruiz sat in the spotlight: “Rocky Mexicano.”

The 29-year-old son of Mexican immigrants, Ruiz became the unlikely heavyweight boxing champion two weeks ago by pummeling and repeatedly knocking down Anthony Joshua, the chiseled, unbeaten British champion making his U.S. debut at Madison Square Garden in an air of preordained victory and on a mission to restore the glory of the heavyweight division.

Since then, fame and riches have come quickly for the paunchy kid with the killer punch from the border town of Imperial, California.

There has been nearly $6 million in earnings. The appearance with Kimmel. A trip to Mexico City to see the president.

Novelist Joyce Carol Oates called boxing “America’s tragic theater,” but the Ruiz story, as far as it goes, offers a stirring alternative and shows that the sport still has the power to inspire.

Even before Ruiz’s upset victory against Joshua, the sport seemed to be on a comeback, with more television money coming in and fans looking ahead to a title fight between Joshua and the unbeaten Deontay Wilder, who holds one championship belt to Ruiz’s four.

A Joshua-Wilder fight had been anticipated as the kind of old-fashioned spectacle that made boxing a global happening before other sports supplanted it, concerns rose over the sport’s damaging health consequences and boxing stars failed to live up to the magnetism of a Muhammad Ali.

Before the fight began, one of the television announcers, sizing up the competitors, said, “Anthony Joshua is the total package. I mean almost a cartoon character. This is how you would draw up the heavyweight champion if you were dreaming it up.

“Andy Ruiz Jr.,” the announcer said, “is not the body beautiful.”

Now, in Ruiz, boxing has a compelling story. He got a chance at the title only after Joshua’s original opponent failed several drug tests, and he delivered an upset on the order of Buster Douglas’ out-of-nowhere knockout in 1990 of the undefeated, undisputed champion Mike Tyson, who entered the fight with 37 victories, 33 of them by knockout.

Ruiz, who was born in the United States and proudly claims his Mexican roots, is now a favorite son for an immigrant community on this side of the border that has been looking for something to celebrate.

“Me becoming the first Mexican heavyweight champion of the world, it’s a blessing,” Ruiz said Monday morning, a big smile on his face as he waited to check in for his flight to Mexico City, carrying two silver briefcases that contained his championship belts.

In his California hometown, Imperial, with its tidy, low-slung homes and desert suburban landscape of bail bonds offices, taco shacks and strip malls, Ruiz’s accomplishment has uplifted a community that feels beleaguered by national divisiveness over immigrants.

“Latinos, we can do something for America,” Andy Ruiz Sr. said on a recent morning. He wore a baseball cap bearing his son’s nickname, the Destroyer, as he sat in his living room, surrounded by trophies and championship belts. “We don’t come here to take the place of the white people. We come here to work, to establish our sons, so they can do something in life.”

For Ruiz Jr., boxing was an inheritance. His grandfather, in the 1960s, ran a ramshackle boxing gym in Mexicali, on the Mexican side of the border, 20 miles south of Imperial. Andy Ruiz Sr. came to the United States as a young boy, fought in the streets of Calexico, California, just across from Mexicali, and later trained boxers, including his son.

Ruiz Sr. had a successful construction business, and when his son’s dedication to boxing faltered, he put him to work in the punishing heat, hanging drywall, to show what a life outside the gym looked like.

He also taught his son a more extreme lesson. After Ruiz Jr. got into another street fight, his father had a friend, a police officer, put him in a jail cell.

“So now he started listening,” Ruiz Sr. said. “He learned to listen.”

If he hadn’t, who knows what would have happened?

“Everybody is tough there because it’s just a small town just near the Mexican border,” said Ruiz Jr., who is likely to fight a rematch against Joshua later this year. “Lots of drug smuggling. There’s gangs. Cartels. But luckily, boxing saved my life. It kept me disciplined, it kept me away from the streets.”

The wider boxing world may have never given Ruiz much of a chance to beat Joshua, but in the gyms of Southern California and Mexico, he had a fearsome reputation as a punishing fighter, even as he was dogged, at times, by questions about his commitment to the sport.

His weight — he fought Joshua at a relatively svelte, for him, 268 pounds — was always an issue. At one point, after failing to qualify for the 2008 Olympics as a member of the Mexican national team, he returned to Imperial and sank into despair, hanging around with old friends and eating too much. His weight ballooned to nearly 350 pounds.

He finally emerged from his funk, took up with a famous trainer, Freddie Roach, of the Wild Card gym in Hollywood, and turned pro, fighting his first professional bout in Tijuana.

Now that Ruiz is a champion, he has sought to make his body shape part of his star appeal.

“Most of us people can identify ourselves through Andy because of the way he looks,” said Manny Robles, his current trainer. “Prior to the fight, nobody believed in Andy. Let’s be real. The great majority of people didn’t think he could win. Look at this guy, he’s chubby, he carries that extra weight. He’s a Mexican heavyweight. There’s never been a Mexican heavyweight champion.”