It is an astonishing fact which sums up the sporting phenomenon that is Michael Phelps – the superhuman swimmer who is now the most successful Olympian of all time.

He's not just breaking world records. The boy from Baltimore is pushing back the frontiers of all sport as he swims with the Gods in the calm waters of China. This is history in the making as Phelps stretches every muscle within his athletic 6ft 3in torso in his quest to achieve what no competitor has done before – and win eight gold medals in a single Olympics.

With three events left, the 23-year-old is on course to sink the "magnificent seven" won by the iconic Mark Spitz in Munich in 1972 – a feat of endurance which sporting connoisseurs claimed would never be beaten.

Until now.

Phelps's performances at Beijing, thus far, can be summed up quite neatly. Five races. Five world records. Five gold medals.

And his twin triumphs yesterday were the 10th and 11th gold medals of his amazing career when his six victories in Athens four years ago are included.

Without a backward glance, he cruised past the nine golds held by four sporting legends – the aforementioned Spitz, athletic warriors Carl Lewis and Paavo Nurmi, and Larysa Latynina, the diminutive Ukrainian who dominated post-war gymnastics.

And, to put the Phelps factor into further context, consider this: Britain has produced six Olympic swimming champions since the war – including Rebecca Adlington's victory this week.

Phelps, on his own, has now won 11. That number could easily be 14 by Sunday. And he's not finished yet. The 23-year-old will still be in his prime in London in 2012.

It is little wonder that talismanic British oarsman Sir Matthew Pinsent, himself no stranger to golden days in the Olympic waters (four to be precise), is adamant that the swimmer's record will be unsurpassable when he does finally hang up his goggles.

The rowing hero believes that the number of gold medals that will eventually hang around the neck of the all-conquering American hero could be in "the high teens".

Admitting that it makes his own herculean record appear quite modest, Pinsent says that only an all-round swimmer of the utmost brilliance and endurance will be able to challenge Phelps's record in some distant decade.

He is right.

Unlike, say, rowers, athletes or boxers who have only one shot at Olympic glory every four years, swimmers are among those who can target multiple events as individuals – and also take their chance in the relay.

And, given this advantage, how then do you compare the respective records of a sprinter and long jumper such as Carl Lewis with the versatility of long-distance runner Paavo Nurmi – the Flying Finn – or the longevity of Sir Steve Redgrave, this country's most successful competitor, whose five rowing golds spanned 16 years and five Games?

Throw into the mix the four gold medals that Jesse Owens won at Berlin in defiance of Adolf Hitler, and Daley Thompson's all-round athleticism in winning back-to-back decathlon gold medals,
and a debate about who is the greatest Olympian is raging faster than it takes Phelps to dive into
the water.

However, this should not be
used to diminish Phelps's place
in history.

For, irrespective of one's sport, you still need supreme reserves of stamina if you're going to contest up to 18 races in eight days – the stamina-sapping schedule that Phelps is now undertaking. He will swim upwards of 60 kilometres in races, warm-downs and training sessions this week, the equivalent of more than 5,000 lengths of the average municipal pool.

He can swim a length in a quarter of the time that it takes the average person looking to stay in shape. I know. I write from personal experience. Previously, I was proud to be able to swim 1,500m every lunchtime. Until I started comparing my own very modest times with those of Phelps.

And, as such, yesterday's
history-making performances demonstrated why one competitor is swimming on planet Phelps and why the remainder – all great athletes in their own right – suddenly look very ordinary.

To the also-rans, this was potentially their only chance of Olympic history. Ever. To Phelps, it was just a routine day in the water.

While his competitors soaked up the atmosphere during the introductions, Phelps was a picture of concentration, dressed in the robes of a boxing gladiator, as he listened intently to his iPod. He was in a world of his own, staring straight ahead.

Yet, within seconds of the 200 metres butterfly beginning, the race was over. Once Phelps had surfaced, his rivals were swimming for second.

This domination stems from his lightning-quick starts – and the fact that his take-off dive is deeper than most, enabling him to kick harder underwater before coming to the surface after 15 metres.

But, having gained this initial advantage, his stroke is so rhythmic that it enables him to glide through the water while his opponents flounder in the wash created by his turbo-charged legs. On this occasion, however, there were many poolside – not least Adrian Moorhouse, Yorkshire's Olympic swimming champion of 20 years ago – who contended that the grimace etched across Phelps's face was evidence that he was tiring from his endeavours.

They were wrong. The winning time was still a world record. But Phelps did show he was human in one respect – his goggles were full of water, a handicap that usually afflicts average swimmers.

"I couldn't see anything for the last 100m," he admitted afterwards. "It just kept getting worse and worse."

To prove that this race was just a blip, Phelps was straight back in the water after collecting his gold medal, the stirring sounds of the American national anthem still echoing around the poolside, as he led off a dominant American quartet in the 4x200m relay, completing the first leg two seconds under world record schedule.

Not many people win two gold medals in a lifetime. Phelps had won two in under an hour. It is little wonder that Barack Obama, the US Presidential candidate, is on holiday in Hawaii this week. Even the great hope of global politics would have been unable to knock swimming's superstar off the front pages.

All Obama could probably have done is sent a text to Phelps – just like those that the record-breaker received from his old High School friends moments before the records of the nine-time Olympic champions were drowned.

"It's ridiculous how many times a day I have to see your ugly face," read one message that reflected the level of hysteria surrounding the swimmer.

Another was more appropriate. "Time to be the best ever," it said.

But what is, perhaps, most astounding is Phelps's ability to handle the pressure as Mark Spitz's record becomes within reach.

Many Britons have a propensity for choking on the big sporting occasion. Not the big American.

As Bill Sweetenham, the no-nonsense former coach of Australia and, more recently, Great Britain pointed out, Phelps combines the perfect physical attributes of a swimmer – a slimline upper body with exceptionally long arms and legs – with a mental toughness that appears impenetrable. Put the two together and it is an unbeatable genetic make-up, said Sweetenham.

Yet, despite the hype, Phelps is still not assured of the eight golds that he so seeks.

He will have to overcome the world-record holder, Ian Crocker, if he is to win the 100 metres butterfly to keep his dream alive.

But Phelps, it should be remembered, is the supreme performer who is used to overcoming the odds.

The son of a single parent, he was diagnosed with Attention Deficit Hyperactive Disorder before he learned to swim.

He could easily have become a tearaway. Yet swimming provided Phelps with a focus. And it did again when he committed a drink-driving offence in the aftermath of his Athens heroics.

Conscious of his responsibilities as a role model, he said with humility: "It was a mistake. It taught me that no matter how old you are, you take responsibility for actions, which I will do."

It was a salutary lesson. Since then, Phelps has simply become better. Even more energy has been poured into his swimming.

This brush with the law, he said, taught him that not many individuals, in any walk of life, have a chance to achieve greatness. Now Phelps is a couple of lengths away from immortality.

"It's not over yet. Anything can happen in the next three events," he said cautiously.

"This is something we have been preparing for for the last four years. All the work is starting to pay off. But I am not unbeatable."

Even if he was to fall short of Spitz's accomplishment, an unlikely outcome based on his accomplishments thus far, his place in history is assured.

"The greatest ever," Anita Lonsbrough, the one-time Huddersfield Council clerk who won breaststroke gold in 1960, told the Yorkshire Post last night.

"I've never seen anyone like Michael Phelps – and I doubt his like will ever be seen again. In any sport."