David Rudisha of Kenya won the men's 800 metres Olympic title on Thursday in a stunning world record of 1min 40.91sec.

The 23-year-old world champion pulled five metres clear of Nijel Amos of Botswana after taking control of the race from an early stage on a warm night in the Olympic Stadium in east London.

He charged down the home straight as the capacity crowd rose to their feet and crossed the line in a time which shaved a tenth of a second off the world record he set two years ago.

Amos timed 1:41.73 - a world junior record for the 18-year-old - to win Botswana's first ever Olympic medal in athletics while another Kenyan Timothy Kitum took the bronze in a personal best of 1:42.53.

It was the first world record in an 800m Olympic final since Cuba's Alberto Juantorena set the mark in the 1976 final.

Rudisha revealed he had visited the Olympic Stadium earlier this year and was shown around by the London Games chief organiser Sebastian Coe, whose world record in the event set in 1981 lasted for 16 years.

"Lord Coe is a very good friend of mine and I was here early in February and he took me round the stadium and I said I would come here and run to make him proud," said Rudisha.

"To come here and break the world record is something unbelievable.

"I was well-prepared this year and I had no doubt about winning. But I was waiting for perfect conditions to break the world record because I knew this year I was in the shape to run 1.40.

"But today the weather was beautiful so I decided just to go for it."

When asked whether he was the greatest 800m runner in history, he said: "Yeah, I'm still running so I believe I'm going to maintain for a couple of years. I want to become a legend in 800."

He said he would attempt to break the world again this year "I get good weather".

Rudisha's victory maintained a family tradition -- his father won Olympic silver in the 4x400 metres relay in 1968 in Mexico.

Coe said the race was one of the greatest ever to have graced an Olympic Games.

"That was simply an unbelievable performance," said Coe, who never won an 800m Olympic gold, though he did win two 1500m titles.

"David Rudisha showed supreme physical and mental confidence to run like that in an Olympic final," Coe added

"Instead of just doing enough to win the race he wanted to do something extraordinary and go for the world record as well.

"Rudisha's run will go down in history as one of the greatest Olympic victories. I feel privileged to have witnessed it in London."

In what was probably overall the fastest two-lap race of all time, seven of the eight finalists set personal bests -- Andrew Osagie's last-place time of 1:43.77 would have been good enough for gold in the 2008 Olympic final.

Rudisha, who had set the previous mark of 1:41.01 in the Italian town of Rieti two years ago, set the pace from the start with Abubaker Kaki of Sudan and Mohammed Aman of Ethiopia in close pursuit.

However, heading down the back stretch he kicked once and had Kaki and Aman struggling to stay in the hunt and another kick at the 300 metres mark had them fighting for the minor medals.

Amos surged into second going into the straight and fought gamely to reel in the Kenyan but in the end settled for his historic silver.

"I'm really happy about it," said Amos.

On breaking the world junior record, he said: "It was my motivation to run against Rudisha so I pushed very hard."