By James Exelby and AFP
Ethiopian and Kenyans dominate the running while women's team events decided.
Ethiopian phenomenon Kenenisa Bekele completed a stunning double Olympic title as he eased home in the men's 5000m to add to his 10,000m victory, while US, Brazilian and Dutch women triumphed in basketball, volleyballand hockey on Saturday.
The 26-year-old Ethiopian emulated compatriot Tirunesh Dibaba's performances in the women's events and he was the first male athlete to do the double since another Ethiopian Miruts Yifter achieved the same feat in the boycotted 1980 Games in Moscow.
Kenya enjoyed a double gold also in the final full session of the track and field programme as they took the men's 800 metres and the women's 1500m.
Wilfred Bungei gave Kenya their first men's 800m Olympic title since William Tanui in 1992.
Virtual unknown Nancy Langat then celebrated her 27th birthday a day late and handed Kenya's women their second title of the athletics - and their second ever - when she cantered to an easy victory in the 1500m.
The Americans regained some pride after an underwhelming competition with golds in both the 4x400m relays while Norway's Andreas Thorkildsen won his second consecutive Olympic men's javelin title.
Belgium's Tia Hellebaut won the women's high jump to give her country their first ever Olympic track and field title.
Bekele stepped on the gas when the bell sounded for the final lap, building up an insurmountable 25-metre lead over Kenyan Eliud Kipchoge down the far stretch.
As he rounded the corner into the final straight, Bekele wagged his finger and grinned broadly as he saw the gap he'd built up.
"It's fantastic," said Bekele. "It's very special, my best accomplishment for sure.
"I am very excited. Olympic gold and record - what more could I want?
"I had just enough energy to make the break. I did that for the people of Ethiopia."
Bungei produced a fine frontrunning performance to land the gold (1min 44.65sec) and prove he can win major titles outdoors as he did indoors when he won the world title in 2006.
Bungei, who was fifth in the 2004 final, edged home ahead of Ismail Ahmed Ismail (1:44.70), who gave Sudan their first ever track and field Olympic medal, while another Kenyan Alfred Yego (1:44.82) was third.
"I came here as the underdog because of the times I ran so far this year," said the 28-year-old Bungei.
"It's been a good night for Kenya. We have done something good here for our country."
Langat ran a tactically astute race as she waited for race favourite and world champion Maryam Yusuf Jamal of Bahrain to make her move to the front, which she did with 500m to go.
Jamal initially looked to have the measure of the Kenyan but down the backstretch the Ethiopian-born Asian Games champion had no answer when Langat passed her.
Coming round the bend there appeared a brief hope the 23-year-old could claw back the ground but Langat, who was a semi-finalist in the 2004 Games, accelerated as she bettered her personal best by over two seconds (4min 00:23sec).
"I knew she [Jamal] would be very strong and I had to work hard to win," said Langat.
Jamal looked round her desperately as she tried at least to hold on for a minor medal but was passed by both Ukrainian duo Iryna Lishchynska (4:01.63) and Nataliya Tobias (4:01.78) and eventually finished fifth.
The American men were runaway winners of their relay, the result never in doubt once individual Olympic champion LaShawn Merritt handed over to second leg runner and 400m hurdles winner Angelo Taylor.
By contrast the American women looked to be down and out going into the final leg.
But a stunning performance by Sanya Richards saw her overhaul Russian Anastasia Kapachinskaya to provide some consolation for only taking bronze in the indiviudal event.
The United States won their fourth straight Olympic women's basketball crown on Saturday with a 92-65 drubbing of Australia in the Beijing Games final.
It was the Americans' third straight victory over Australia in an Olympic final, and the third straight win by a double-digit margin.
Also indoors, Brazil's women's volleyball team put an end to years of heartbreak by winning the Olympic gold medal for the first time in their history here Saturday, defeating the United States by three sets to one.
Their 25-15, 18-25, 25-13, 25-21 victory in a high-class final came after three straight semi-finals and successive bronzes at the 1996 Atlanta Games and in Sydney four years later.
"We struggled a lot," said Brazil's Sheilla Castro. "We played hard and we never gave up. Only in the second set we played badly.
"It hasn't hit me that we've won."
Defeat put paid to a fairytale finish for US coach Lang Ping, a member of the China side that beat the United States in the 1984 Olympic women's volleyball final in Los Angeles.
The Dutch took gold in the women's hockey beating China 2-0 and South Korea won what could be the last Olympic baseball gold medal, dethroning three-time champions Cuba 3-2 in a dramatic final.