Tszyu takes on American Tony Harrison for the interim WBO super welterweight title in Sydney on Sunday afternoon and can call himself a world champion, albeit an interim one, if he wins.It’s the biggest fight of the his career but the 28-year-old’s father, former light-welterweight champion Kostya Tszyu, won’t be ringside watching his son in action.Watch undefeated Aussie superstar Tim Tszyu return to the ring for his biggest fight yet versus USA’s former world champion Tony Harrison for an Interim WBO Super Welterweight title LIVE Sunday March 12. ORDER ON MAIN EVENT ON KAYO SPORTSKostya hasn’t exactly been a consistent presence in Tim’s life since leaving his wife and kids to start a second family in Russia over a decade ago and Tim is happy to keep it that way.The 53-year-old surprised Tim by flying in to watch his professional debut in 2016, but he hasn’t been ringside for his son’s fights since.Tim didn’t enjoy his dad barking instructions at him from the other side of the ropes,