Ethiopian Kenenisa Bekele sprinted to victory in the 5,000 meters on Saturday to become the first man to complete the Olympic long-distance double since 1980.
The 26-year-old, who retained his 10,000 title last Sunday, raced home in an Olympic record time of 12 minutes 57.82 seconds to clinch his first major 5,000m gold and match the double of compatriot Miruts Yifter in Moscow 28 years ago.
Kenyan Eliud Kipchoge was unable to follow Bekele when the world record-holder broke for home after the bell and finished second in 13.02.80. His compatriot Edwin Cheruiyot Soi took bronze in 13.06.22.
Bekele, who won silver in Athens four years ago, gave Ethiopia a sweep of the long-distance events at the Games after Tirunesh Dibaba sealed the women's double on Friday.
Bungei delivers at last
Kenyan Wilfred Bungei finally claimed the major title his talent has promised for years when he won the Olympic 800 meters gold with a dominant front-running performance on Saturday.
The 28-year-old, ranked number one in the world six years ago, is still the fifth-fastest 800 runner of all time with his 2002 best of one minute, 42.34 seconds.
He took silver in the 2001 world championships but missed out on medals in two more worlds and the 2004 Olympics and had begun to earn a reputation as a big-race choker.
Winding up his pace he opened a three-meter gap that proved just enough to hold off fast-finishing Ismail Ahmed Ismail of Sudan in a time of 1:44.65 seconds.
Ismail took silver with another Kenyan, world champion Alfred Kirwa Yego, finishing fast to claim the bronze.
Kenya's Langat wins women's 1500m
Kenya's Nancy Jebet Langat won the gold medal in the women's 1500 meters at the Bird's Nest stadium on Saturday in a time of four minute 00.23 seconds.
In an open field, Ukraine took silver and bronze medal positions through Iryna Lishchynska and Nataliya Tobias.
Favorite Maryam Jamal of Bahrain led until she was overtaken by Langat, who had stuck tightly behind her, with 250 meters remaining.
Jamal, the current world champion, faded badly and missed out on a medal position, ending up in fifth place.
The Ethiopian-born runner said she had felt ill. "What happened? I was sick," she said.
Langat, who only made the semi-finals in Athens four years ago, timed her move to perfection, having the acceleration to take the lead and the endurance to keep the Ukrainians at bay.
Thorkildsen defends javelin crown
Norway's Andreas Thorkildsen defended his Olympic javelin title with a gold medal victory on Saturday.
Thorkildsen threw a 90.57 meters with his fifth effort to make sure he kept Latvia's Ainars Kovals, who threw a personal best of 86.64, in the silver medal position.
World champion Tero Pitkamaki of Finland had to settle for bronze medal after a best throw of 86.16 meters.
The 26-year-old Thorkildsen's throw was a new Olympic record and marks a return to the top for the Norwegian after his second-place finishes in the last two world championships.
US win women's 4x400 relay
Sanya Richards surged past her Russian rival in the final few meters to help the United States win the gold medal for the women's 4x400 meters relay on Saturday.
Richards teamed up with Mary Wineberg, Allyson Felix and Monique Henderson to win in a time of three minutes 18.54 seconds.
Russia finished second in 3:18.82 after Anastasia Kapachinskaya started the last leg with a handy lead over Richards.
Jamaica won the bronze medal in 3:20.40.