Conor McGregor had a three-word reaction to Anthony Joshua’s KO of Francis Ngannou.

Joshua stopped Ngannou in two rounds.

It sent shockwaves around the boxing and MMA world with McGregor left in awe as he commented on Joshua’s Instagram post.

He wrote: “Nah man. Madness.”

McGregor, 35, was ringside in October when Ngannou, 37, made his boxing debut against Tyson Fury.

And he astonishingly dropped Fury, 35, only to lose a controversial split-decision.

But Joshua, 34, made no mistake in restoring order in the ring with the savage KO, leaving Ngannou’s future in boxing up in the air.

Although the heavyweight star insisted his business in boxing is not over yet.

Ngannou said: “You can be sure I’m not done here. It was not my day. He was way better than me.

“It sucks, but it’s the game. We all know that.”

Joshua embraced with Ngannou moments after the stunning KO and even urged him to remain in boxing.

He said: “You’re an inspiration. ‘You’ll beat a lot of people. Don’t leave boxing. Don’t leave boxing.”

Joshua, 34, then added: “If you need anything, let me know, but we’ll speak another time.”