KSI defeated his fellow internet star in the first round in front of a bumper London crowd.
Speaking after the bout, KSI called out Jake Paul, but not before competing in another "warm-up fight" - possibly against former David Haye opponent Joe Fournier.
Speaking to DAZN when asked about his next bout: "Joe Fournier, (Tyron) Woodley, Slim (Albaher), whoever it is - I'll destroy.
"I need to be tested. I need more tests before I reach the final level... Jake f***ing Paul."
KSI defeated Paul's brother - and Prime energy drink business partner - Logan Paul in 2019 in his only other professional boxing bout.
Jake Paul was quick to respond on social media, tweeting "I love when KSI wins because it gives him more confidence for him to actually get in the ring with me."