Tszyu (right) beat Mitchell for a second time

The Australian, who had not fought for 22 months, stopped Mitchell in the third round to retain his IBF title.

Tszyu sent his opponent to the canvas with a straight right in the second round and asserted his authority again with another massive right.

Mitchell fought on gamely, but referee Raul Caiz was then forced to intervene.

Tszyu, 35, improved his record to 31-1, while condemning Mitchell to his fourth loss in 59 pro fights.

American Mitchell also lost the pair's first encounter in 2001.

I believe the two years off has only added longevity to my career Kostya Tszyu

And he was unable to take advantage of a small vertical cut over the inside of Tszyu's left eye, the product of an accidental head butt in the first round.

British WBU holder Hatton was on hand to stake his claim to a crack at the Australian champion's crown, as was WBA champion Vivian Harris.

And Tszyu, who had previously hinted at retirement, talked up his chances of fighting on, saying he would take on "any big names" in the division.

"I believe the two years off has only added longevity to my career," he said.

"I am smarter than I was. The time off gave me a lot of time to think. I know how to fight, and I studied and worked very hard for this. It was two years in the making."

Tszyu added: "I told you I had a surprise, but I never expected this fight to end so early.