Joshua Buatsi delivers ruthless performance in first fight under Virgil Hunter
"I took him seriously. I landed the shot at the right time. Most importantly I hope he is OK."
The 2016 Olympic-medalist extended his record to 14-0 and won his first fight under American trainer Virgil Hunter in style.
Buatsi was headlining the card after Terri Harper was forced to pull out from her unification bout against Hyun-Mi Choi because of a hand fracture.
The 28-year-old, returning for the first time since grinding out victory over Marko Calic, produced a vicious overhand right followed by another right hand to send Dos Santos to the canvas.
Joshua Buatsi consoles a distraught Daniel Blenda Dos Santos [Mark Robinson/Dave Thompson/Matchroom Boxing]
Doncaster delight in Manchester
Punch perfect performance by Richards
Undercard results
The former Team GB standout, who has shared sparring with the likes of unified heavyweight world champion Anthony Joshua and European champion Joe Joyce, completely dominated Manev, earning a 60-54 decision from the referee.