Corrie Sanders: Heavyweight world champion

Sanders in 2007 during the penultimate fight of his career (EPA)

Corrie Sanders was not a man accustomed to displaying emotion, but he burst into tears when returning from Germany after shocking the boxing world by obliterating the high-flying Wladimir Klitschko to win the World Boxing Organisation heavyweight title in 2003. He was expecting the usual family delegation to meet him at the airport but this time he was greeted by the roar of hundreds of fans, black and white, headed by his friend, the former flyweight champion "Baby Jake" Matlala.

"I'm just so proud to be a South African," he said between sobs, later explaining: "I just couldn't hold myself. I was so amazed that so many people came out for me."

The Afrikaner, then 37, was a modest man, refreshingly free from hubris, or from any hint of racial prejudice. A decade earlier, for example, in the dying days of apartheid, I invited him to join me on a trip to Soweto to visit Matlala, who had just won a world title. He didn't hesitate, and the 6ft 4in heavyweight and the 4ft 10in flyweight had a whale of a time together. He sometimes noted that he had more black South African fans than white – and seemed genuinely delighted when they would stop him in the street to wish him well.

His moment of glory in Hamburg took just three minutes and 27 seconds. By then he had dropped Klitschko four times, leaving him helpless. But in the end, it proved to be a solitary high-water mark in a 46-fight career (42 wins including 31 knock-outs) that never quite lived up to its potential.

Sanders was an extraordinary natural athlete. At 20 he played rugby union at centre for Northern Transvaal B (then South Africa's leading provincial side), ran the 100 metres in 10.9 seconds and went on to become a pro-am golfer with a one handicap, regularly shooting sub-par rounds. He also played a mean game of tennis, and generally preferred talking about football, cricket and rugby than anything pugilistic.

One of three children growing up in a working class family in Brits, near Pretoria, he started boxing at the prompting of his father and uncle and took to it effortlessly, ending up with an amateur record of 180 wins and 11 losses. He turned professional in 1989 as an alternative to a career in the police and soon showed his potential. He was fast on his feet for a big man, with sharp reflexes and wonderful hand-eye coordination, excellent defensive skills, and knock-out power in both hands. But his chin was dodgy and his dedication erratic.

He racked up 23 straight wins, his victims including Britain's Johnny Nelson along with several American fringe contenders. But three weeks after his country's maiden democratic election, he was poleaxed in two rounds by the American Nate Tubbs.

The rebuilding process involved regular forays to the US and Britain, and over the next six years he registered 13 wins, including 11 knock-outs. But he turned down advice to advance his career by relocating. "I love my country too much to move to the US like other boxers," he said.

Finally, in 2000 he was put in with a top contender, Hasim Rahman. Sanders outboxed him for a couple of rounds, but it turned into an atavistic brawl with both men tasting the canvass. In the seventh Rahman's greater desire, conditioning and resilience told. He went on to beat Lennox Lewis for the world title; Sanders languished without a fight for 18 months.

He returned to stop the future British champion Michael Sprott in one round, but it looked like his moment had passed until Klitschko, the dauphin of the division, offered him a shot at the lightly regarded WBO title. The 40-1 outsider was considered too old and fragile for a giant who was 10 years younger, two inches taller and 18lb heavier, but Sanders used a sports psychologist to motivate him and trained as never before.

He also listened to the advice of his friend, Lennox Lewis. "He told me not to hold back and said I should pressure Klitschko from the first bell and he wouldn't be able to handle that, and he was right. Then, after the fight, he phoned to congratulate me. I really appreciated that call."

It should have been the start of big things, but contractual problems and injury kept him out for 14 months, and he returned undertrained and overweight to take on Wladimir's harder brother, Vitali. Still, he managed to wobble the giant Ukrainian before being stopped in eight. After three more wins and a loss he retired aged 42 to concentrate on his business interests and on the fairways.

He was celebrating his nephew's 21st birthday at a restaurant in Brits when a gang of robbers burst in and opened fire. Sanders dived in front of his daughter to protect her and was shot in the stomach and hand. He was rushed to hospital but died soon after – one of around 50 people who, on average, are murdered in South Africa each day. "I think he died a hero," said his ex-wife, Sunette.

Cornelius Johannes Sanders, boxer: born Brits, South Africa 7 January 1966; married Sunette Sanders (marriage dissolved; one son, one daughter); died Brits 23 September 2012.