By Thomas Gerbasi

Ford Amphitheater, Coney Island, New York - The apprenticeship of Errol Spence Jr. is now over, as the rising welterweight star knocked out veteran Leonard Bundu in the sixth round Sunday at the Ford Amphitheater in Coney Island, earning himself a shot at the IBF 147-pound title currently held by Kell Brook.

And after back-to-back knockouts of Bundu and former world champion Chris Algieri, it's clear that 'The Truth' is ready for the championship level.

Bundu pressured Spence at the opening bell, a tactic quickly defused by the southpaw, who began pecking away at his opponent with shots to the body and head. Bundu's unorthodox style and insistence on switching stances kept Spence from landing more than one clean blow at a time, but it was a clear round for the former Olympian.

Italy's Bundu kept trying his best to make it ugly in the second and third rounds, which prompted Spence to start digging to the body in order to slow him down.

Early in the fourth, Spence made Bundu stumble with a shot upstairs, which only made the veteran fire back harder in an attempt to get even. Most of Bundu's return fire was deflected, but he did get in the occasional shot that got Spence's attention. The Texan was starting to sit down more on his punches as the round ended, though.

In the fifth, Spence's technical game began to shine, as he was a step ahead of Bundu throughout, even though it was a competitive battle to this point.

An apparent knockdown in round six was called a push by referee Johnny Callas, but when Bundu rose, he was clearly rattled. That's all Spence needed, with his follow-up assault, capped off by a right hook, sending Bundu down even more emphatically. This time, Callas didn't even need to count, as he waved the bout off at the 2:06 mark.

"He certainly lives up to the hype," Bundu said. "Errol was more precise than Keith Thurman. With Keith, every shot is a power punch. You feel them. Errol threw more, but they didn't all hurt."

With the win, Spence moves to 21-0 with 18 KOs; Bundu falls to 33-2-1 with 12 KOs.

"I am one of the top fighters at 147 pounds," Spence said. "With this performance, I proved that again today. I want to fight for a title next. I would want to fight Kell Brook, but if he doesn't go down in weight, he vacates or is stripped, I don't care, I just want to fight for the belt."

ON THE UNDERCARD

Popular Brooklyn welterweight Julian Sosa got a fight out Nebraska's Rene Marquez, but still did more than enough to win a six-round unanimous decision.

Scores were 59-55 twice and 58-56 for Sosa, now 6-0-1 with 2 KOs; Scottsbluff's Marquez falls to 5-3 with 2 KOs.

Backed by an entire section of fans, Sosa used his height and reach advantage to keep Marquez at bay early, and by the middle rounds, he had rocked his foe a couple times and seemed to have him on the verge of a stoppage. But Marquez hung tough and kept battling, making it to the final bell, which was at least a moral victory.

Wichita's Chris Harris was willing throughout his cruiserweight six rounder with Far Rockaway's Joseph Williams, but Williams was a step ahead all night as he punched his way to a shutout unanimous decision win.

All three judges saw it 60-54 for Williams, now 10-0 with 7 KOs; Harris falls to 2-1-2 with 2 KOs.

In the junior middleweight opener, Brooklyn's Chordale Booker made it 3-0 as a pro with a shutout four-round decision over Brandon Black.

Going the distance for the first time, Booker tried to get Black (1-2) out of there, but the game Kansas product refused to go away, despite falling short on the scorecards by tallies of 40-36 twice and 40-35.