Michael Phelps finally realised what he has achieved today, as the emotional American became the greatest Olympian of all-time.

Two more gold medals in the Water Cube this morning lifted him to 11 and a place in the history books - and with three more on offer the 23-year-old may push his record haul to heights that may never be broken.

"I think I am almost at a loss for words," he said after claiming the 200 metres butterfly and was part of the USA team that won the 4x200m freestyle relay. "Growing up I always wanted to be an Olympian. Now to be the most decorated Olympian of all time . . . I'm speechless.

"I just kept thinking 'Wow'. It's a pretty great title, it's pretty neat, I'm definitely honoured.

"When you have an Olympic gold medal, it stays forever. Your always an Olympic gold medallist, It's amazing and it definitely never gets old.

"Listening to the anthem with the medal around your neck is an amazing feeling."

Such is his feat that Phelps currently lies in fourth place in the medals table on his own behind China, the USA and South Korea.

Nor is the mania surrounding Phelps confined to Beijing, judging by the activity on his mobile phone.

"I got like 80 text messages today," he added. "One of my friends said to me, 'Dude, how many times a day do I have to see your ugly face?'. The last text I got before I race today was, 'It's time to be the best ever.'

"It's pretty cool having the whole country behind you and on your side."

Gold No10 - the one that lifted him above Carl Lewis, swimmer Mark Spitz, Finnish distance runner Paavo Nurmi and Soviet gymnast Larissa Latyninain the Olympic pantheon - was in his favourite event, the 200m butterfly.

Yet, despite breaking the world record, Phelps was not happy with his swim and was clearly unhappy as he left the pool and ripped off his goggles.

Ever the perfectionist, the Baltimore Bullet wanted to swim faster but had water in his eyes.

"When my goggles filled up there was nothing I could do," he raged. "I could just keep on swimming, that's all.

"I tried to see something at the finish, the wall, and I tried to see the "T" on the bottom [of the pool] to judge my turn.

"I was more or less trying to count my strokes, hoping I was dead on.

"I handled the situation the best way I could, but I'm disappointed, I know I can go faster than that." It came as no surprise then that Phelps - who won six golds in Athens four years ago - returned within an hour in the 4x200m relay and tore up the pool on the opening leg as the Americans smashed the previous world record by five seconds to leave him on 11 golds.

Phelps added: "When I was at the award ceremony for the butterfly, that's when I started thinking about it and that was when I started tearing up."

Phelps insisted afterwards that he was not "unbeatable" - with the 100m butterfly on Saturday posing the biggest potential danger to his eight-medal target.

He said: "Anything can happen in the next three events. But I've got almost everything I could have asked for and I think under the circumstances I have handled myself pretty well. This is something I have been working on for the last four years and it is starting to pay off. But no-one is unbeatable."

Before today's remarkable events he had already won the 400m individual medley final, 4x100m freestyle relay and the 200m freestyle.

There are no finals for Phelps tomorrow as his gruelling schedule of 17 races over nine days continues and he insisted he has the stamina to last the pace.

"That's probably the biggest thing I have learned over the last three or four years, to conserve my energy," he added.

He also had time to pay tribute to his coach Bob Bowman adding: "I don't think I would be where I am today with any other coach. He's always on top of things, we've been through a lot."