Sadam Ali (R) fighting Michael Clark on the April 19 undercard of Bernard Hopkins vs. Beibut Shumenov in Washington, D.C. Photos by Nicholas Kamm/AFP-Getty Images.

WASHINGTON — Brooklyn-based welterweight Sadam Ali dropped veteran Michael Clark with a hard right, left hook duo that resulted in a first-round knockout on the Showtime Extreme portion of Saturday's Bernard Hopkins-Beibut Shumenov undercard at The D.C. Armory.

A 25-year-old nicknamed "World Kid," Ali (19-0, 12 knockouts) finished off Clark (44-10-1, 18 KOs) after referee Joe Cooper counted him out at the 2:06 mark. Ali had last been in the ring for a sixth-round stoppage of Jesus Selig in December.

Also on the Showtime Extreme card was 23-year-old Marcus Browne (10-0, 7 KOs) of Staten Island, N.Y., scoring a fifth-round knockdown during his eight-round unanimous decision over Otis Griffin (24-16-2, 10 KOs), winning 80-71 on all three cards.

A 21-year-old Brooklyn resident, junior welterweight Zachary Ochoa (7-0, 4 KOs) floored his man with a fourth-round right hand, and again with a left to the body in the fifth, where the corner of Hector Marengo (6-8-4, 4 KOs), of Puerto Rico, waved an end to the fight.

Cooper stopped it at 1:32 of the fifth.

Hopkins-Shumenov is the main event of a tripleheader on Showtime that will also feature undefeated WBO middleweight titleholder Peter Quillin against Lukas Konecny, as well as an IBF welterweight title bout matching titleholder Shawn Porter against ex-beltholder Paulie Malignaggi.

In non-televised bouts, middleweight Dominic Wade knocked out Marcus Upshaw with a devastating right hand at 2:11 of the second round, and lightweight Jose Valderrama pulled an upset over Chrisshawn Alexander, who was recently signed by advisor Al Haymon.

In still another fight, super middleweight D'Mitrius Ballard scored a second-round technical knockout over Quincy Miner, who was dropped in the round and succumbed to a shoulder injury at the 2:35 mark.

In yet another welterweight bout, David Grayton dropped Howard Reece once during a first-round knockout, and lightweight Lamont Roach Jr. won his pro debut by unanimous decision over Victor Galindo.