Video shows he then appeared to strike Smith repeatedly before being pulled off by other wrestlers.
Rampage Jackson later responded on social media, external and claimed Smith was “awake and stable”.
In wrestling parlance, a ‘work’ is a fight that is staged or scripted, and Rampage said this incident was a “work that went wrong”.
“Raja was unexpectedly hit in the side of the head by him moments before Smith’s match,” said the former UFC light heavyweight champion.
“Raja was told that he could get his ‘payback’ in the ring. I thought it was a part of the show. It was bad judgement.”
Rampage, 47, also said his son had suffered a concussion from sparring “only days ago” and had “no business doing anything remotely close to physical contact”.
“Raja is an MMA fighter, not a pro wrestler, and had no business involved in an event like this,” he added. “I don’t condone my son’s actions at all.
“As a father, I’m deeply concerned with his health and the wellbeing of Mr Smith. I’m very upset that any of this happened, but my main concern now is that Mr Smith will make a speedy recovery.”
Rampage apologised to Smith and to Kick on behalf of his son, who has had three amateur and two pro MMA fights.
There has been no confirmation from the organisers on Smith’s condition.
Knokx Pro is a wrestling school that has WWE ID designation, meaning WWE will provide it with support and opportunity. It has been approached for comment.