LONDON (AP) — Hours before the world's fastest men bid for a sprint relay world record, two-time world champion Sergei Kirdyapkin claimed an Olympic record in the 50 kilometer race walk, the longest event in the track and field program.
The victory gave Russia its fifth gold to further cement its second-place standing in the track and field medals table behind the overpowering Americans, who have eight. In a packed evening program there are seven more Olympic titles at stake before Sunday's closing men's marathon.
Walking through a glorious morning sunshine in 21 C (70F) heat at the Mall, in front of Buckingham Palace, Kirdyapkin crossed in 3 hours, 35 minutes, 59 seconds to slash 1 minute, 10 seconds off the Olympic record of 2008 champion Alex Schwazer, the Italian who was kicked out of the London Games because of doping.
Australia's Jared Tallent finished 50 seconds behind to get the silver and Si Tianfeng of China got the bronze.
Saturday evening, Usain Bolt will be happy to cut just .01 of a second off the 4x100-meter relay world mark his Jamaican team set last year.
For all the excitement that Bolt has already generated at the Olympics, one thing is still missing for him in London: a world record. It has flashed up twice already in other events in yellow on the stadium time clock: "WR" — for the men's 800 meters and the women's 4x100 relay.
In Beijing Bolt had three world records to go with his three gold medals. After just missing out during his golden 100 and 200 meters in London, he will have to count on his teammates to help him in the 4x100 relay.
On Friday, they proved they were ready.
With Bolt resting up, his Jamaica relay teammates easily qualified for Saturday's final in 37.39 seconds.
The American team trumped them with 37.38 seconds for a U.S. record, the fourth best time in history and proof that the sprint relay will be much more than just a Jamaican race against the clock.
On Saturday, Bolt will have the chance to show if he can make enough of a difference on the fast track in the finale of the weeklong U.S-Jamaican battle for sprint supremacy.
While Bolt is still waiting to set a world best time in London, others have beaten him to it.
Allyson Felix won her second Olympic gold medal and added a world record for good measure as she helped the U.S. women's relay team power past its Jamaican rivals in the 4x100 meters. One day earlier, David Rudisha of Kenya set a new mark in the 800.
"This isn't the end for me," Felix said. While Bolt will be seeking his third gold Saturday, so will Felix in the 4x400 relay. "It's just going to be exciting," she said.
The 200-meter champion ran a blistering second leg and 100-meter silver medalist Carmelita Jeter finished off the world record performance, pointing to the time clock with her mouth wide open as soon as she got past the finish line, seeing that the 27-year-old mark of the former East Germany was gone.
The U.S. team finished in 40.82 seconds, shaving a massive 0.55 seconds off the old mark.
"To look up and see we had a world record, it was just crazy," Felix said. "I didn't think that was going to happen."
Almost as amazing as the U.S. women's 4x100 relay record was the stunning loss by the U.S. men's 4x400 relay after it had won every Olympic gold medal in the event since boycotting the 1980 Moscow Games.
In a thrilling finish, Ramon Miller of the Bahamas chased down and swept past Angelo Taylor in the final straight to deprive the United States of a gold it long thought it had a lock on.
"I tried to kick and come home. Unfortunately, Ramon had more than I did," said Taylor, a two-time Olympic champion in the 400-meter hurdles.
Such was the surprise that it overshadowed Oscar Pistorius' last race at the London Games. Pistorius, known as the "Blade Runner," got the South African baton in last place and crossed the line in eighth in an anticlimactic performance after he became the first amputee runner in track and field to compete at the Olympics.
"It has been incredible to be here," said Pistorius, a double amputee who runs with the aid of carbon fiber blades. "Just to participate has been great and now I am really looking forward to the Paralympics."
One favorite who lived up to the billing was Renaud Lavillenie of France, who won pole vault gold with an Olympic record jump of 5.97 meters.
Former world-record holder Tatyana Lysenko of Russia, who served a two-year doping ban until 2009, set a games record of 78.18 meters to win the hammer throw.