Adam Kownacki uses power to stop Gerald Washington in Round 2

Heavyweight Adam Kownacki, right, stayed unbeaten with a TKO victory over Gerald Washington, left, in Round 2. Al Bello/Getty Images

NEW YORK -- Heavyweight contender Adam Kownacki's legion of Polish fans were decked out in the red and white of their flag and going mad for his every move on Saturday night, and Kownacki rewarded them with a punishing, second-round knockout of Gerald Washington.

The Poland-born, Brooklyn-based Kownacki, who could be a close to a shot at world titlist and ringside observer Deontay Wilder, just walked through Washington in the co-feature of the Premier Boxing Champions on Fox card headlined by the Keith Thurman-Josesito Lopez welterweight world title fight at Barclays Center in Brooklyn.

"I trained hard for this fight. I prepared for 10 hard rounds, but I'm glad I got it done and ended it as fast as I did," Kownacki said. "We stuck with the game plan. I'm a pressure fighter. I worked on sitting down on my punches, and I proved that I have great power when I do that. It's amazing to have this support from the Polish fans. It definitely gives me extra energy."

Kownacki (19-0, 15 KOs), 29, a bona fide attraction at Barclays Center, had a huge first round as he teed off on Washington over the final 30 seconds. He hurt him and backed him up with a right hand and then landed a slew of right hands after that. Washington was buzzed and on the ropes in major trouble when the round ended.

Washington (19-3-1, 12 KOs), 36, of Vallejo, California, tried to take it to Kownacki to open the second round, even opening a cut over his left eye, but his attack was quickly blunted as Kownacki landed a big right hand to drop Washington. He barely beat the count, and referee Harvey Dock gave him ample time to recover before the fight resumed.

When it did, Kownacki wasted no time, hammering Washington with a series of heavy punches that forced Dock to step in and stop it at 1 minute, 9 seconds. After the stoppage, Kownacki mimed putting a belt around his waist.

It was another notable win for Kownacki, who first hit the world scene in July 2017 with a fourth-round knockout of countryman and former world title challenger Artur Szpilka. Kownacki followed with an action-packed, sixth-round knockout of Iago Kiladze last January. Then, he outpointed former world titlist Charles Martin last September before pummeling Washington, a former pro football player.

Washington got a title shot against Wilder in 2017 and suffered a fifth-round-knockout loss followed by an eighth-round-knockout loss to top contender Jarrell "Big Baby" Miller in the year. He fought just once in 2018 and won a decision over John Wesley Nofire before suffering the most one-sided defeat of his career to Kownacki.

Nyambayar wins title eliminator

Featherweight Tugstsogt Nyambayar, a 2012 Olympic silver medalist for Mongolia, stepped up in opposition and won a hard-fought unanimous decision over former interim titlist Claudio Marrero to earn a world title shot.

Nyambayar won 116-111, 115-112 and 114-113 in the elimination bout to become the mandatory challenger for 126-pound titlist Gary Russell Jr. ESPN.com had it 116-111 for Nyambayar.

"We had a really good camp, so this is just me putting the pressure and pace that we worked on in camp and using it in the ring," Nyambayar said. "This sets me up for big fights. Whatever big fights are presented to us, we'll take it."

Nyambayar (11-0, 9 KOs), 26, who fights out of Los Angeles, landed a right hand in the third round that badly wobbled Marrero. He took a few more shots right after the big one but managed to stay on his feet. Nyambayar landed a solid left just before the end of the round that hurt Marrero (23-3, 17 KOs), 29, a southpaw from the Dominican Republic, again.

Nyambayar stalked forward for most of the fight, and Marrero tried to counter him, making for a hefty dose of back-and-forth action. Nyambayar, who had some swelling on his left cheek, seemed to land the harder punches.

When Marrero nailed Nyambayar with a punch after referee Benjy Esteves had clearly ordered them to break during the 10th round, he penalized Marrero one point. When the action resumed, Nyambayar unloaded a flurry of punches on Marrero, including a low blow for which Esteves warned him.

They embraced before the 12th round and immediately traded clean punches, both clearly thinking the fight was still up for grabs. Nyambayar continued to land, and with 35 seconds left, raised his hands as though he had already won the fight.

Also on the undercard

  • Flashy and fast Brooklyn junior lightweight Chris Colbert (10-0, 3 KOs), 22, won a hard-fought but clear unanimous decision over Josh Hernandez (8-2, 7 KOs), 23, of Chicago.

    Colbert, who came to the ring with his hair dyed pink, won 79-73 on all three scorecards in a fight that featured a lot of holding and grappling. But when Colbert was able to find room to punch against Hernandez, he tattooed him with clean, quick shots.

    Colbert more than doubled Hernandez in punches landed, 160-72, according to CompuBox statistics.

    "He put up a great fight. Today, I decided not to give the crowd a boxing lesson. I decided I wanted to show them that I can stand and fight with anybody if I choose to," Colbert said. "We're going to keep making these fights easier and easier. I have very high-quality fight, and I'm getting better and better as we go."

  • Junior welterweight Gary Antuanne Russell (8-0, 8 KOs), 22, a 2016 U.S. Olympian from Capitol Heights, Maryland, and the younger brother of featherweight world titlist Gary Russell Jr. easily destroyed Roberto Almazan (7-9, 2 KOs), 20, of Brownsville, Texas, in the second round.

    Russell, with his older brother serving as his trainer, scored three knockdowns against the utterly overmatched Almazan. Russell dropped him to knee in the first round from an accumulation of punches and then decked him twice more in the second round with a right hook on top of the head and then another accumulation of punched moments later. After the third knockdown referee Shada Murdaugh waved off the fight at 59 seconds.

    "I listened to my corner's directions, and they told me that the hook was going to be there when he shot his left hand. I went to my hook position, and I was ready to catch and fire," Russell said. "This is nothing new to me. I just try to execute what I'm told and sharpen my craft."

  • Middleweight Chordale Booker (14-0, 7 KOs), 27, a southpaw from Stamford, Connecticut, dropped and easily outboxed Juan De Angel (21-10, 19 KOs), 31, of Colombia. De Angel, who has losses against super middleweight world titlist Caleb Plant and former junior middleweight titleholder Austin Trout, was the best opponent of Booker's career, but Booker won handily. He dropped him late in seventh round with a left hand to the body and won 80-71, 79-72 and 79-72.

  • Cruiserweight William Deets (7-12, 3 KOs), 33, of Kearney, Nebraska, scored an upset fourth-round knockout of Marsellos Wilder (3-1, 2 KOs), 29, of Tuscaloosa, Alabama, the younger brother of heavyweight world titlist Deontay Wilder, who watched at ringside. Marsellos Wilder appeared to be winning a sloppy, slow-paced fight going into the fourth and final round when Deets nailed him with a left hand and a right for a hard knockdown. Wilder beat the count, but his legs were gone, and when he fell into the ropes on the other side, referee Al LoBianco waved off the fight at 2 minutes, 35 seconds.

  • Featherweight Stephen Fulton (15-0, 7 KOs), 24, of Philadelphia, dropped Marlon Olea (13-4, 12 KOs), 25, of Colombia, three times en route to a fifth-round knockout victory. Fulton knocked him down with a left hook in the second round and a left uppercut with a few seconds left in the fourth round, and when he landed another left to floor him in the fifth round, referee Murdaugh stopped the fight at 1 minute, 41 seconds.

  • Middleweight Mark Duncan (3-0, 3 KOs), 31, of Clarksburg, Maryland, stopped a bloodied Daniel Flores (0-3), 26, of Albuquerque, New Mexico, on his feet at 1 minute, 15 seconds of the third round.

  • Welterweight Tyrek Irby (6-0, 2 KOs), 25, of Landover, Maryland, won a hard-fought decision over Jonathan Figueroa (2-2, 1 KO), 27, of Hartford, Connecticut. One judge had it 40-36, and the other two had it 39-37.

  • Super middleweight Mycheal Teal (2-0, 2 KO), 24, of St. Petersburg, Florida, knocked out Jacob Landin (0-3), of San Antonio, with a left hook to the body 30 seconds into the fight.