Callum Smith scored scary KO of Lenin Castillo who was left shaking and stretchered from the ring on Anthony Joshua vs Oleksandr Usyk undercard

Callum Smith made a statement on his light-heavyweight debut last time out with a frightening knockout of Lenin Castillo.

The former WBA super-middleweight champion looked impressive in his first fight at 175lbs, which took place on the undercard of Oleksandr Usyk’s victory against Anthony Joshua.

The pair are set to rematch on Saturday night, live on talkSPORT, and Smith’s next bout against Mathieu Bauderlique will be on the undercard.

Ian Walton/Matchroom

Eddie Keogh/Matchroom

Against Castillo, Smith’s celebrations were quickly halted.

Smith hammered Castillo with an overhand right in round two which saw him collapse backwards to the canvas.

He lay on his back shaking and the referee instantly waved the fight off.

Medical staff responded quickly and attended to Castillo, who was stretchered from the ring minutes afterwards.

Mark Robinson/Matchroom

Thankfully, positive updates followed after the worrying scene.

Eddie Hearn revealed Castillo was ‘responsive’ as he left the stadium to go to hospital.

Smith was beaten by Canelo Alvarez last year, but is now looking to make an impact in his new weight class.

Speaking after the final bell, ‘Mundo’ admitted it was unpleasant to see his Dominican foe in such distress.

Matchroom Boxing

“It’s not nice. I celebrated before and then I realized how bad it was,” Smith (28-1, 20 KOs) told reporters after the fight.

“That’s the last thing you want to see. Boxing is a tough enough sport as it is and we all have families to go home to.”

If he beats Bauderlique on Saturday night, he will become the WBC mandatory challenger to unified champion Artur Beterbiev.

Usyk vs Joshua 2 on talkSPORT

talkSPORT will be in Jeddah for the Oleksandr Usyk vs Anthony Joshua rematch on Saturday, August 20.

Join us – for FREE – for exclusive radio coverage of the huge heavyweight fight that has the WBA, WBO and IBF titles on the line.

Our expert team will be made up of presenters Adam Catterall, Gareth A Davies and Ade Oladipo, commentator Andy Clarke, former bantamweight champion Spencer Oliver and current heavyweight star Derek Chisora.

We’ll be ringside in Saudi Arabia from 8pm – don’t miss it!