Nikita Tszyu climbs off the canvas to KNOCK OUT arch rival Dylan Biggs in the toughest fight of his career as telltale sign at weigh in proved crucial to Aussie star's big victory

Nikita Tszyu was forced to haul himself off the canvas to knock out his arch rival Dylan Biggs in his toughest fight of his career.

The new Australian super welterweight champion joked that he is set for the bright lights of Las Vegas, with his world champion older brother Tim Tszyu now a star in the United States. 

'It's a beautiful feeling, I've been envisioning this moment, picturing how it would play out,' he told the crowd with the belt around his waist.

Tszyu was knocked down in the first round before rallying for a big finish in the fifth, and admitted he is a slow starter and needs to cop a few punches to get going.

'He was standing there like a wall I had to climb over,' he said of Biggs, but revealed how he altered his gameplan to get the decisive knockout.

'When my jab started landing. I noticed he was getting gassed ... trying to hit me with pot shots from a distance. I had to set traps for him and hit him as he attacked.'

Asked what's next, he laughed and said, 'Vegas, baby!' while looking at his brother Tim.

'My heart was beating quite fast,' Tim admitted of how he felt when Nikita got knocked down. He suggested his younger brother should take on Tony Harrison, the man he knocked out in Sydney, next time out.

While Biggs appeared the bigger man in the ring, fans couldn't help but notice a major clue at the pre-fight weigh in may have proven crucial to Tszyu's victory.

The broad-shouldered Biggs's body frame is far slimmer around the waist, leading to the Tszyu camp convinced that targeting the body would be the route to another win. 

The victory extended 25-year-old Tszyu's record to 8-0, with six of his wins coming via knockout.

In the co-main event, Issac Hardman restored his reputation as "The headsplitter" with a punishing TKO victory over Troy Coleman to claim the vacant WBO Intercontinental middleweight title.

After winning his first 13 professional fights, Hardman had lost two of his past three to Michael Zerafa and Rohan Murdock before hitting back with a vengeance.

Coleman was saved by the bell after copping a barrage in the fourth round before the referee wisely stopped the fight early in the fifth.

Earlier, Brandon "The Bull" Grach delivered the Australian knockout of the year to upset the previously undefeated Liam Talivaa in an explosive heavyweight bout.

Grach, a one-time teenage amateur prodigy who only returned to the ring in September after a 13-year boxing hiatus, ended Talivaa's night just four seconds into the second round with a thunderous left hook.

There were concerns for Talivaa as he lay prone, motionless on the canvas after being knocked out cold, but he eventually came to.

Talivaa was caught out prematurely celebrating with a throat-slitting gesture after dropping Grach in the first round.

But in a major statement to heavyweight top dogs Justis Huni and Joe Goodall, Grach responded almost immediately to send Talivaa crashing to the floor with a big right late in the opening round, then again early in the second.

More to follow.