Former two-division world champion Carl Frampton believes Daniel Dubois should be heavyweight champion after a controversial fifth round in his world title fight with Oleksandr Usyk.

On Saturday night in Poland, Dubois landed a big shot to the body which sent Usyk down in pain for several minutes. The referee, Luis Pabon, ruled it as a low blow.

Several replays of the connecting punch would create a lot of debate among fans, and fighters, with a lot of observers calling it a legal blow or borderline.

Frampton was among those who felt Dubois connected with a legal punch.

"When I saw it, it didn't look low to me. That was not a low blow. That was a body shot. He should have been counted out. Daniel Dubois should be unified heavyweight champion right now. I still don’t think it was [a low blow after watching the replays]," Frampton added.

"The shot was borderline, some referees would say it was low and others would let you get away with it. For me it wasn’t low, Usyk has used his experience and taken a body shot. That did not hit the part that he has led us to believe it hit him, he has taken a body shot, he has thought I can get away with pretending this is low. He took a rest because he has been hit by a bodyshot."

However, there were also many - like former world champion Liam Smith - who felt the punch strayed a bit low.

"It was low, whether his protector is high or not - which should of been pulled at the start of the fight if team Dubious felt it was high - it’s just below waistband. Yes, Usyk milked the time he was allowed but, no one can answer whether he stays down if the ref counts it," Smith stated.

Usyk would eventually recover from the fifth round drama. He dropped Dubois at the end of the eight and finished him off with a right hand in the ninth to retain the WBO, IBF, IBO, WBA titles.