Watch: Anthony Joshua's devastating punch that knocked out Helenius

British boxer Anthony ‘AJ’ Joshua produced an outrageous and brutal knockout against Robert Helenius on Sunday morning at the London O2 Arena.

After a cautious six rounds, AJ delivered a seventh-round sucker punch that felled the Finnish to send the initially angry fans in loud cheers.

The fans had earlier in the fight booed him for being too cautious, but the knockout was just in time to shut them out.

At the time of the knockout, the 33-year-old was bleeding from the nose.

"I want to give Helenius a round of applause for saving the show," Joshua was quoted by DAZN after the triumph.

"This is my time in the ring, and I told Helenius to come again because he had talent, and I had to work him out."

Joshua now has 26 victories, including 23 knockouts in 29 professional fights and three losses.