NEW YORK — Unbeaten southpaw junior bantamweight prospect Jonathan “La Bomba” Gonzalez of Cuagas, Puerto Rico, dropped Jose Rivera of New Rochelle, N.Y., with a second-round right hook but had to settle for his first unanimous decision victory before a screaming capacity crowd of about 4,425 at WaMu Theater inside Madison Square Garden on Saturday night.

Nicknamed “La Bomba,” Gonzalez won, 60-53 on the cards of two judges and, 59-54, on that of the third to improve to 6-0 with five knockouts, while Rivera is 3-4-2 with no knockouts.

Southpaw former feathweight titleholder Juan Manuel Lopez, also of Puerto Rico, entered the ring with Gonzalez for support.

Gonzalez-Rivera took place on the undercard of an HBO-televised main event featuring WBO and WBC bantamweight titleholder Nonito Donaire (26-1, 18 KOs) defending his belts opposite WBO junior bantamweight titleholder Omar Narvaez (35-0-2, 19 KOs).

In the night’s opening bout, Brooklyn welterweight Cletus Seldin scored his fourth win without a loss and his second knockout at 2 minutes, 52 seconds of the second round over Jose Segura Torres (2-3-2, 1 KO) of Miami.

The second welteweight fight, Quebec, Canada’s Mikael Zewski took only a minute and 27 seconds to dispatch of Keuntray Henson (4-4, 1 KO) of Memphis. Zewski rose to 11-0 with his seventh knockout, and his second straight stoppage victory.

Zewski is managed by Cameron Dunkin, whose list of stars includes Nonito Donaire, Brandon Rios, Tim Bradley, Alfredo Angulo, Mikey Garcia, Kelly Pavlik, Pawel Wolak and James Kirkland.

The third bout of the evening featured crowd-pleasing Long Beach, New York-based lightheavyweight Sean Monaghan (10-0) scoring his seventh knockout over Pennsylvania’s Anthony Pietrantonio (7-8, 5 KOs) at 2 minutes and 51 seconds of the fifth round.

The stoppage was the third straight in as many consecutive wins from Monaghan, whose nickname, “Irish,” was being chanted by the crowd members throughout the fight.

Monaghan battered Pietrantonio for much of the fight until trapping him on the ropes, nailing him with a hard right to the body and finishing him with two, clubbing overhand rights to the jaw. At that point, referee Eddie Claudio had seen enough and came to the rescue.

Another local favorite is Long Island welterweight Tommy Rainone (16-4, 4 KOs), who ground out a six-round unanimous decision over Denver’s Brad Jackson (13-7-1, 7 KOs) in the evening’s fifth bout. Rainone earned the victory, 58-56, 59-55, and, 60-54.

Oceanside, N.Y., lightweight Mike Brooks (6-0, 1 KO) maintained his spot-less record with a four-round, unanimous decision over Eddie Ramirez (6-10-1, 3 KOs) of Laredo, Texas, winning, 40-36, on the cards of all three judges.

Photo by Chris Farina, Top Rank Inc.

Lem Satterfield can be reached at [email protected]