Ethiopia's Meseret Defar sprinted past compatriot Tirunesh Dibaba last night to reclaim the Olympic women's 5,000m title she won in 2004.
Dibaba, chasing an Olympic distance double-double after retaining her 10,000 title last week, had no response to Defar's turn of speed and faded to third as Kenya's world champion Vivian Cheruiyot overtook her before the line.
"It's a great day for me. Since 2008, I have tried everything as I wasn't able to win the Olympics," Defar, the bronze medallist from Beijing, said.
"I have won two Olympic medals before and this is my third. I'm not sure I can do a fourth so this means a lot to me," added the 28-year-old.
Dibaba hit the front with four laps to go after a slow first half followed by Defar, Gelete Burka and the three Kenyans in the race who moved up on the outside.
The field started to string out as Dibaba began to test her rivals and at the bell, only Defar, Kenya's Sally Kipyego and Cheruiyot had gone with her. But victory over in the longer race a week ago appeared to have taken its toll as Dibaba's usual searing final lap did not materialise and Defar remained on her shoulder ready to pounce on the home straight.
Defar crossed the line with her arms in the air before kissing a religious picture she had carried in her top and falling to the track weeping.
Asli Cakir Alptekin of Turkey won the gold medal in the women's 1,500m.
Russia's Tatyana Lysenko, who watched the 2008 Olympics on TV while serving a two-year doping ban, won the women's hammer gold with an Olympic record throw of 78.18 metres.
Lysenko, who won the world championship title last year, beat the old Olympic record of 76.34 with her first throw of the night, 77.56m, then improved it with her fifth.
Heading into the final weekend of the London Games, the US tops both the gold and overall medals races after trailing the Chinese for most of it.
The US beat Argentina 109-83 in the men's basketball semi-finals game last night. They now face Spain.