Former WBA super-middleweight champion Callum Smith returned to the squared circle this afternoon for a bout with Lenin Castillo.

Smith (28-1) was returning to action for the first time since suffering a unanimous decision loss to pound-for-pound boxing great Canelo Alvarez in December of 2020.

Meanwhile, Lenin Castillo (8-1) was attempting to keep his perfect record in tact when he squared off with Callum Smith. The Dominican native had scored a fifth round TKO victory over Emilio Cayetano in his previous effort.

Tonight’s Smith vs. Castillo fight took place at the Tottenham Hotspur Stadium in London, England. The result was a nasty second round knockout for the British standout, as Callum destroyed Lenin with a right hand.

Check out the footage below on Twitter:

British boxer Callum Smith 31Yo, knocks out Lenin Castillo;

The 33Yo Dominican fighter, was left unconscious & shaking on the canvas after suffering a brutal second-round KO against Callum Smith in their bout in London, he was reportedly conscious, but was rushed to hospital. pic.twitter.com/faqvQWiS3A

— @KassMedefer (@KMedefer) September 25, 2021

https://twitter.com/CultureMMA_/status/1441846477899321347

Lenin Castillo had to be stretchered out of the ring and given oxygen following the scary knockout. Thankfully it is being reported that the Dominican fighter is now conscious and in the care of medical professionals.

Who would you like to see Callum Smith fight next following his nasty knockout victory over Lenin Castillo this afternoon in London? Share your thoughts in the comment section PENN Nation!