BEIJING - Usain Bolt won a third gold medal and made it a world record triple Friday when Jamaica capped its overwhelming dominance in the Olympic sprint events with the title in the 4x100 relay.

"Go Asafa!" Bolt shouted after handing the baton to Asafa Powell, who powered through to finish in 37.10 seconds, a stunning .30 seconds better than the 16-year-old mark of the United States.

Bolt had already set the world record of 9.69 in the 100 and 19.30 in the 200, but that funky Jamaican was aching for an encore.

And Powell, a former 100 world record holder who has had a disappointing Olympics so far, provided it. He crossed the line almost a full second in front of silver medallists Trinidad and Tobago, which finished in 38.06. Japan took the bronze in 38.15.

"I said to Asafa, 'Can we do this?' And he was like, 'Don't worry, man, we got this one."' Bolt said.

The loss of the world record made the great American sprint debacle complete, failing to get a single gold in six events.

If Bolt was again all about the shiny golden shoes, oversize celebrations and wiggling dances to reggae, Tirunesh Dibaba achieved a landmark almost as impressive in total serenity.

The Ethiopian claimed an unprecedented long-distance double, winning the 5,000 metres to achieve something Ethiopian greats like Haile Gebrselassie and Kenenisa Bekele have been unable to do.

In an intense battle with rival Meseret Defar, Dibaba kicked for home with 500 metres to go. Defar, the defending champion, just cracked.

Defar was even passed by Ethiopian-born Elvan Abeylegesse of Turkey, who claimed her second silver after she was beaten by Dibaba in the 10,000, too.

Bekele is going for a similar double in the 5,000 on Saturday, after barely missing out four years ago.

Crossing the line, Dibaba timidly clenched her fists, briefly raised her arms in triumph and quickly turned around to console her rivals.

Just ahead of Bolt's triple, Jamaican sprinters finally proved they were fallible, however, botching the handover of the baton in the women's 4x100 relay they were overwhelmingly expected to win.

"I did what I was supposed to do, she did what she was supposed to do," said Kerron Stewart, who botched the handover with Sherone Simpson. "I guess it wasn't God's will."

Russia profited, unexpectedly adding another gold, and Belgium got its first medal of the Olympics when European champion Kim Gevaert followed close behind. Nigeria took bronze.

The United States was eliminated in the heats.

Maurren Higa Maggi earned Brazil a gold medal in the women's long jump.

The world indoor silver medallist led from the first round at 7.04 metres and it proved enough for gold.

World and defending Olympic champion Tatyana Lebedeva of Russia, who took silver in the triple jump, got another silver, finishing only one centimetre behind the Brazilian on her final attempt.

Blessing Okagbare of Nigeria took bronze, a bigger blessing than it seems.

She was only allowed into the final after Lyudmila Blonska was disqualified after failing a doping test in the heptathlon, where she had won silver.

"I'm shocked," Okagbare said. "It is the biggest miracle."

Carolina Kluft, the three-time world champion and 2004 Athens Olympics heptathlon champion, finished ninth.

Unlike Kluft, Bryan Clay is sticking with the multi-event test of power and speed which traditionally is called the battle to become "the world's greatest athlete."

The 2004 Olympic silver medallist and 2005 world champion won with 8,791 points.

Andrei Krauchanka of Belarus took silver with 8,551 points, and Leonel Suarez of Cuba was third with 8,527.

Roman Sebrle of the Czech Republic, the reigning world and Olympic champion, finished sixth.

Dan O'Brien was the last U.S. athlete to win the Olympic decathlon, taking gold at the 1996 Atlanta Games.

Steve Hooker won the pole vault to give Australia its first in track and field at the Beijing Olympics.

After winning with a vault of 5.90, he added an Olympic record at 5.96.

World indoor champion Yevgeniy Lukyanenko of Russia took silver at 5.85 and Denys Yurchenko of Ukraine got bronze.

Under a clear sky and increasingly hot sun with morning temperatures approaching 30 C, Alex Schwazer of Italy won the longest event on the program, the 50-kilometre walk.

With a break 10 kilometres from the finish, he pulled away from the leading group and held on to beat Jared Tallent of Australia, who won bronze in the 20K.

Denis Nizhegorodov of Russia, the silver medallist from the Athens Games and world record holder, took bronze.

Schwazer finished in 3:37:09, slicing 1:20 off the 20-year-old Olympic record.

Schwazer was third at the last two world championships when he blamed bad tactics for missing gold.

This time, he was part of a leading group of four in the initial breakaway and then took off on a solo burst. Confident enough, he raised a finger for No. 1 to the Italian fans lining the course with less than three kilometres to go.