Mike Tyson, with his entire career on the line, flirted with disqualification and fought like a six-round novice but produced as good a knockout punch as he has thrown in a decade to end Francois Botha's hopes in the fifth round of a dramatic contest in Las Vegas early yesterday. A near capacity crowd had been stunned by the sheer ineptitude of Tyson's attempts to cope with Botha's effective, if limited, attacks but marvelled at the devastating power he produced to save the fight which had been slipping away from him in so disastrous a manner.

The 32-year-old former champion's quick temper was always likely to be a significant factor in the outcome, and memories of his shameful disqualification against Evander Holyfield 19 months ago flooded back as the bell sounded to end an opening round which had been won clearly by the South African.

With Botha's left arm trapped under Tyson's right, Tyson twisted and began to throw punches at his opponent's head with his free left hand as Botha bulldozed into him. For 20 seconds they grappled as cornermen tried to help the referee pull them apart in chaotic scenes as armed police leapt up to the ropes to seal off the ring.

"I think he was trying to break my arm," said Botha afterwards. "He's right," joked Tyson about an incident which was anything but amusing, especially for those who recalled the near riot which followed his second meeting with Holyfield.

The referee Richard Steele, so often a controversial figure in the past, deserves immense credit for his control of an explosive situation as he visited Tyson's corner to deliver a stern warning: "You've done it once before Mike, don't let it happen again," leaving no doubt that he was considering another disqualification.

And, as the mauling continued in the second round, with Tyson seeming more intent on head-butting his opponent than throwing legitimate punches, Steele stepped in to deduct a point from Tyson on the judges' scorecards. One more transgression, and it would have been all over.

The psychiatrists who had advised the Nevada State Athletic Commission that Tyson was fit to return to the ring must have cringed as the fighter seemed hell-bent on another orgy of self- destruction.

Botha stuck to his game plan, forcing Tyson on to the back foot whenever possible and continually goaded his opponent into ever more embarrassingly wild charges. Like a crazed old pit bull, Tyson flailed and raged while being tagged repeatedly by an elementary left-jab/right-cross attack.

After four rounds Botha was already five points ahead on two judges' cards, an extraordinary margin in a fight where so many "experts" had suggested the South African would be outclassed. Tyson had not won a round and was beginning to flag - no more than a shell of the man who had once terrorised the heavyweight division - prompting dark mutterings that a once great talent had been reduced to that of an imposter whose out-of-step fumblings were those of a shot fighter.

"It was too easy and I got overconfident," Botha said afterwards. And, in the fifth round he had chosen stupidly to stand in front of Tyson, arms down, sneering contemptuously as he openly ridiculed his assailant. Muhammad Ali, watching from ringside, could have got away with it but Botha is no Ali.

Tyson's mild-mannered trainer Tommy Brooks said later: "Mike had been looping his punches and head hunting, so I told him he had to throw his shots straighter and go to the body."

But one of the oldest boxing maxims, that the last thing a fighter loses is his punch, was never more vividly illustrated than by the blow Tyson landed to end the fight. A short right exploded on to the left side of Botha's jaw, leaving the White Buffalo flat on the canvas. Though Tyson had done precious little right, at least now he rushed across the ring to check his opponent's well-being before offering words of consolation.

"He was cool, he was a great fighter," said Tyson. "There was a tremendous amount of ring-rust there for me tonight but I was okay."

He may have thought his performance was acceptable but Botha had shown that no decent fighter will be intimidated by Tyson after his humiliation against Holyfield. The burly South African is a strong, uncomplicated man who simply believed in himself enough to glimpse an improbable win. Next time Tyson may not be so fortunate when he attempts to call up a power punch to get out of trouble.

He could be back in the ring on April 24th, when his most likely opponent is the durable, light-punching German Axel Schultz, although 50-year-old George Foreman is trying to drum up interest in a meeting which could prove considerably more marketable in this improbable world.

Once more Tyson insisted he could retire after just three more fights, saying he found it unacceptable to have his life continually analysed. "People should show me respect and stop writing trashy articles," he said. "They try to assassinate my character but I'm a human being and I need love like everybody else."

Botha won considerable respect in defeat and said he hoped for a re-match which, for once, is not impossible. Through his promotional tie-up with Frank Warren he has been pencilled in as a challenger to the winner of the World Boxing Organisation version of the world heavyweight title fight in Newcastle on February 13th, when Britain's Herbie Hide defends his hitherto lightly regarded title against the American Orlin Norris.

If Botha won that, a Tyson rematch could follow, with the winner moving on to fight Holyfield early in the year 2000. Holyfield-Tyson III remains a promoter's dream, the biggest foreseeable fight by far.