The last time live boxing appeared on CBS, Leo Santa Cruz wasn’t watching.

But it’s not that he wasn’t interested. It’s just that, well … he was only 8 years old.

Now 24, the Mexican-born body-punching specialist will both defend his 118-pound world championship and end the network’s decade-plus ring drought when he faces challenger Alberto Guevara on Saturday afternoon at the Los Angeles Memorial Sports Arena.

The two-bout broadcast, which begins at 4:30 p.m. ET, will also feature the pro debut of 2012 U.S. Olympian Joseph Diaz Jr. against seven-fight veteran Vicente Alfaro in a four-round 122-pound fight. It’s being presented by Oscar De La Hoya’s Golden Boy Promotions, which is putting on a nighttime card from the same venue that will be televised by Showtime Extreme at 9 p.m. and Showtime at 10:30 p.m.

“Boxing is on a great roll (after) a great, exciting fight (last) weekend with Manny Pacquiao and Juan Manuel Marquez,” De La Hoya said. “Now boxing is moving on to a bigger stage in terms of viewership and people watching on free TV. Boxing is back on CBS.”

It’s the first live boxing event on the network since Bernard Hopkins knocked out Glen Johnson to retain his International Boxing Federation (IBF) 160-pound championship at the Fantasy Springs Casino in Indio, Calif. on Jan. 20, 1997.

The sport was a popular weekend staple on CBS in the 1980s, featuring the memorable announcing team of Tim Ryan, Gil Clancy and Sugar Ray Leonard and making household names of fighters like Ray “Boom Boom” Mancini. In fact, Leonard’s first pro fight was broadcast by CBS in 1977 and De La Hoya appeared on the network as an unbeaten prospect in 1994.

Calling the action for Saturday’s card are Al Bernstein, Mauro Ranallo and Paulie Malignaggi. Bernstein, who was inducted into the International Boxing Hall of Fame earlier this year, called Santa Cruz “one of the most exciting fighters in boxing, and one of the busiest.”

Add most convenient, too, because he lives in the East L.A. neighborhood of Lincoln Heights, less than 10 miles from Saturday’s venue.

“Considering that six months ago I was just a guy fighting on undercards, to now being picked to headline and defend my title on network television is hard to believe,” said Santa Cruz, a professional since 2006. “But I am so happy. It is a tremendous honor and something I am not taking lightly. This is such an unbelievable opportunity. To fight on CBS is the greatest exposure you can get.”

He won the IBF’s vacant bantamweight title on June 2 with a punishing decision over Vusi Malinga on the undercard of a Showtime event from the Home Depot Center in suburban Los Angeles, and has since defeated Eric Morel (TKO 5) and Victor Zaleta (TKO 9) in dominant fashion on Showtime broadcasts in September and November.

Santa Cruz took all 12 rounds on two official scorecards and 11 of 12 on a third against Malinga in the championship victory. He then forced the 36-year-old Morel to quit on his stool after five rounds, handing the former 112-pound title-holder the first stoppage loss of a 16-year career.

Against Zaleta, he scored knockdowns in rounds seven and eight and ultimately prompted referee Ray Corona to stop the fight without a count when he floored Zaleta again with a straight right in the ninth.

The wins improved him to 22-0-1 with 13 knockouts.

“(Santa Cruz has had) a pretty incredible 2012,” said Stephen Espinoza, executive vice president and general manager of Showtime Sports. “(He) has gone from Extreme to Showtime Championship Boxing and now to CBS. He deserves every second of the attention he’s getting because he is a fighter who fights his heart out for the entire fight.”

Guevara, meanwhile, is a largely unknown commodity making his first professional appearance outside Mexico. He was not among the top 15 fighters at 118 pounds in the IBF’s most recent rankings and has had only one fight of 16 in his career – he’s 16-0 with six knockouts – scheduled for more than eight rounds.

He weighed 118 pounds while earning a unanimous 10-round decision over Khabir Suleymanov on April 14 in Rosarito, Mexico, then ballooned to a career-high 136¾ for an eight-round decision against countryman Raul Hidalgo in his last fight on Aug. 4 in Mazatlan.

His brother, Pedro, fought for the IBF’s title at 108 pounds on the Mazatlan card and lost a split decision.

"I understand that there are not a lot of people who know about me,” Guevara said, “but I've always felt that if I continued to do my job in the ring the attention would come little by little. With this opportunity I can get a lot of recognition right away. I look forward to being able to showing fans what I can do. I have big plans to defeat Santa Cruz. I'm looking at Saturday as an early Christmas for me."