LOS ANGELES -- Robert Guerrero's nickname is "The Ghost," and that's just what he's been the past 11 months because nobody has seen him fight during the long layoff.
It's been a rocky year for Guerrero. He went through a lengthy arbitration with former promoter Dan Goossen before winning his case and signing with Golden Boy Promotions in mid-December. Guerrero also spent much of his time out of the ring caring for his leukemia-stricken wife, Casey, who is now in remission.
With the promotional battle behind him and his wife doing better, Guerrero returned to the ring at the Staples Center on Saturday night's Antonio Margarito-Shane Mosley undercard and made quick work of Mexico's Edel Ruiz (29-22-5, 18 KOs).
Guerrero (23-1-1, 16 KOs) knocked him out with a left to the body 27 seconds into the scheduled 10-round bout.
Guerrero, 25, a two-time featherweight titlist, was moving up to the 130-pound junior lightweight division.
He will return to action quickly as part of HBO's March 7 "Boxing After Dark" card in San Jose, Calif., which is not far from his hometown of Gilroy. His opponent has not been selected yet.
"I can't wait to get back into the ring. It was too short," Guerrero said. "After waiting all year, I can't wait to get back in. That's what happens when you stay in shape. I saw him lunging with a punch and I landed a beautiful body shot and it was over."
" Super middleweight prospect Matvey Korobov (3-0, 3 KOs), a two-time amateur world champion and 2008 Russian Olympian, impressively stopped Jose Florentino at 2:28 of the first round.
Korobov, 26, Top Rank's star signing out of the Beijing Olympics who has relocated to Florida, punished Florentino with an assortment of hammering blows until knocking him to his knees with a right-left combination. Florentino made it to his feet, but was in no condition to continue and the fight was stopped.
" Cincinnati lightweight prospect Adrien Broner (6-0, 5 KOs), a 19-year-old who fights like his rear end is on fire, overwhelmed Mexico's Jose Lugo (10-7-1, 5 KOs) with nonstop aggression during their six-round fight, but Broner was taken the distance for the first time.
Broner, however, won an easy unanimous decision, 60-54, 59-55 and 58-56.
Broner looked like he might stop Lugo in the opening round as he rushed him and doled out a brutal assault. But Lugo survived despite never being in the fight.
Dan Rafael is the boxing writer for ESPN.com.