Harrison was completely laid out by Sprott's surprise left hook

Harrison, 35, was knocked out in the third round by a huge left hook from Sprott and has now lost three fights in 14 months.

Harrison began well and floored Sprott with a solid combination in round one.

But Sprott landed some good jabs in the following two rounds before delivering the telling blow to set up a world title eliminator with Matt Skelton.

Despite the defeat, Harrison said he still felt he could make a comeback.

I'll be back and hopefully I will have a chance to rectify it with Michael Sprott Audley Harrison

"Definitely," said Harrison. "I knocked him down first round which made me go away from the game plan a little bit and I didn't respect his power.

"I'll rectify it. I made a mistake tonight - he caught me with a shot fair and square which is boxing."

Harrison, the 2000 Olympic champion, had suggested his stuttering professional career was getting back on track with a three-round stoppage of Danny Williams in December.

He started confidently enough against Sprott and looked on course for a quick win after putting the Reading man down in round one.

But Sprott made it to the bell and came out strongly in the following round before shocking everyone in the third.

I want to fight Matt Skelton and get the world title Michael Sprott

Harrison was still flat out as the count was completed and he took some time getting to his feet as a delirious Sprott wildly celebrated retaining his European Union heavyweight title.

"I was convinced (I could win)," said Sprott. "What he had done to Danny Williams, he thought it was it, and I knew it wasn't.

"Anyone who put money on the bookies - enjoy!"

And Sprott insisted that a rematch with Harrison was not on the cards.

"I want to fight Matt Skelton and get the world title," he said. "I've had enough of rematches - I'm moving on."

However Harrison said he was hoping there was still a chance of a rematch.

"All credit to Michael Sprott because I didn't see the shot coming," he said.