Klitschko retires

World heavyweight champion Vitali Klitschko has announced his retirement due to injury.

The Germany-based Ukrainian, who holds the WBC belt, postponed his defence against American Hasim Rahman for the fourth time after spraining his right knee in training last week.

Klitschko, 34, came under heavy criticism for the withdrawal from the fight, which was scheduled to take place in Las Vegas this weekend.

After failing to respond to medical treatment, Klitschko has called it a day having failed to defend his belt since mauling Britain’s Danny Williams almost a year ago.