Lenin Castillo was stretchered out of the ring following his second-round knockout loss to Callum Smith at Tottenham Hotspur Stadium in London on Saturday.

According to Martin Domin of the Daily Mirror, Castillo received "lengthy medical treatment" before he was removed from the ring.

Smith caught Castillo with a stiff right hand, and Castillo's legs began twitching once he hit the canvas.

Michael Benson of TalkSport was informed by event promoter Eddie Hearn that Castillo was responsive and conscious and that he went to the hospital for precautionary measures.

Portland Trail Blazers star Damian Lillard was among those who expressed well wishes for Castillo after the scary knockout:

The fight took place on the undercard of the heavyweight title bout between champion Anthony Joshua and challenger Oleksandr Usyk.

Smith, who is a 31-year-old native of England, was making his light heavyweight debut after primarily fighting at super middleweight previously.

With the knockout win, Smith improved his career record to 28-1 with 20 wins by way of knockout. Castillo is a 33-year-old native of the Dominican Republic and had his career record fall to 21-4-1 in defeat.

In addition to being his light heavyweight debut, Saturday marked Smith's first fight since suffering his first career loss to Canelo Alvarez in December.