LOS ANGELES - Oscar De La Hoya and Golden Boy Promotions hosted the official weigh-in for Saturday's stacked 10-fight card at StubHub Center in Carson, Calif. The first live bout is at 2 p.m. PT.

In the main event of a tripleheader live on SHOWTIME® (10 p.m. ET/7 p.m. PT), former four-division world champion Robert "The Ghost" Guerrero (31-2-1, 18 KOs), of Gilroy, Calif., returns from a 13-month layoff to face offensive-minded, hard-hitting Yoshihiro Kamegai (24-1-1, 21 KOs), of Sapporo, Japan, in a 12-round welterweight bout. Guerrero came in at 146-pounds and Kamegai weighed in at 146.8

The co-feature on SHOWTIME CHAMPIONSHIP BOXING is a clash of exciting southpaws, undefeated yet untested Gary Russell Jr. (24-0, 14 KOs), of Capitol Heights, Md., against perhaps the most prolific amateur boxer of all-time, Vasyl Lomachenko (1-1, 1 KO), of Ukraine, in a 12-rounder for the vacant WBO Featherweight World Championship. Both Russell and Lomachenko came in at 125.4-pounds.

The telecast will open with former two-division world champion Devon Alexander (25-2, 14 KOs), of St. Louis, facing the always-dangerous Jesus Soto Karass (28-9-3, 18 KOs), of Los Mochis, Sinaloa, Mexico, in a 10-round super welterweight match. Alexander weighed in at 148.2-pounds and Soto Karass came in at 148.