The murder trial of sports star Oscar Pistorius got its first taste of showbiz razzmatazz when boxer Kevin Lerena took to the witness stand.

Known as the KO Kid, Lerena, 22, cut an impressive figure with his bulky frame squeezed into a well-cut suit on Wednesday.

The cruiserweight boxer was called to give evidence at his friend Oscar Pistorius's trial for murdering girlfriend Reeva Steenkamp on Valentine's Day last year.

He eschewed the option of not having his face broadcast on television from the courtroom at North Gauteng High Court. Being comfortable in the spotlight is par for the course for the young figher who insists he is "on the way to glory" on his Twitter page.

Lerena also seems to have the appetite for a battle, saying in one interview: "There's nothing better than fighting."

The young fighter, half-Argentinian, is still very much in the early stages of his boxing career, having turned professional soon after leaving school. So far his record is impressive, with nine wins from nine bouts – including six knockouts.

Pistorius might even count himself thankful to still have Lerena as a friend, after the paralympian shot him in the foot by accident only weeks before Steenkamp was killed last year. The shot, fired shortly before Lerena was scheduled to fight, had no adverse impact, as Lerena went on to chalk up a victory.

Outside the ring Lerena is also a qualified fitness coach, who is shaping up as a marketing department's dream by appearing very happy to give sponsors more plugs than a bathroom showroom.

But his own profile outside of the boxing world was low, until he was thrust in to the global spotlight by his Pistorius's murder trial.

In the aftermath of Steenkamp's killing, Lerena took to the airwaves to defend Pistorius and his version of what happened on the fateful night he shot his model girlfriend.

Describing Pistorius as "very loving person," Lerena spoke of having seen the disabled runner and Steenkamp shortly prior she was killed. He told Piers Morgan on CNN: "When I saw them together in Cape Town, they really were in love. Oscar was a very loving person, as well as Reeva. So by no means did I think their relationship was in jeopardy.

"They're loving and you know, like I said, it's very sad because it was a big shock to us to hear what happened, to wake up that Valentine's morning and to hear the shock to all South Africans and many people around the world."

Lerena defended Pistorius's gun hobby as normal among his circle of friends. The fighter said: "Oscar obviously was a collector and a few of his friends are collectors as well. But he carried his own handgun obviously for his own self-protection.

"You know, after all, around the world, there are bad parts in every country and every city. And it's a good form of self-defence, whether it's a false sense of security or not. A lot of people in South Africa carry guns for self- defence."