Ethiopia's Almaz Ayana ran away from her rivals to smash the women's 10,000-metre world record for Olympic gold as athletics at the Rio Games got off to an extraordinary start on Friday.
The 5,000m world champion Ayana pulled away shortly after the halfway mark in perfect conditions but in front of a sparse crowd to triumph in 29 minutes 17.45 seconds.
She took 14 seconds off the mark of 29:31.78 that China's Wang Junxia had run 23 years ago in Beijing 1993, a record which was rated untouchable.
"This means everything for me," Ayana said. "Getting to this point is a dream come true. I never thought that this would happen and I'm so in awe. I'm very happy to get here."
Only four other runners had run below 30 minutes over the years but didn't come within 20 seconds of the time of Wang, who was in February revealed to have admitted to doping many years ago in the team under controversial coach Ma Junren.
But on Friday Kenya's Vivien Cheruiyot took silver in 29:32.53, two-time 10,000m Ethiopian gold medallist Tirunesh Dibaba grabbed bronze in 29:42.46, and fourth-placed Kenyan Alice Nawowuna also dipped below 30 minutes on 29:53.51 in an astonishing race.
The fast times may, however, raise questions at a time when the entire Russian athletics team is suspended from Rio over doping practices, and Kenya and other nations have been hit hard in this area as well.
But Ayana insisted: "Firstly, I did my training specifically based on the 5000m and 10,000m. Number two, I praised the Lord. The Lord gives me everything, my every blessing. My doping is my training, my doping is Jesus. Otherwise, nothing - I am crystal clean!"
The second gold of the day went to China's Wang Zhen who topped the 20km race walk in 1 hour 19 minutes and 14 seconds (1:19:14) from compatriot Cai Zelin (1:19:26) while Dane Bird-Smith of Australia kept Brazilian home team walker Caio Bonfim off the podium by five seconds, taking bronze in 1:19:37.
Wang, who broke away with three kilometres left, got gold at last after two world championship silvers and an Olympic bronze in the past.
The day's other final in the evening is the women's shot put.
Kenyan 800m runner Ferguson Rotich meanwhile advanced into the semi-finals as it appeared that his coach John Anzrah had committed no wrongdoing at all after being suspected of providing a sample and signing in the runners' name - after being looked into by the International Olympic Committee.
Compatriot superstar David Rudisha, the multiple world and 2012 Olympic champion, whose world record run of 1:40.91 was one of the highlights of the London 2012 Games, led the 800m heats in 1:45.09.
There was bad news for the German team when their 2012 Olympic and three-time world discus champion Robert Harting failed to qualifify for Saturday's final - his 62.21m effort after two fouls not good enough.
Like at many other events at the Games, there were plenty of empty seats in the Olympic Stadium, a stark contrast to London 2012 where every athletics session had been packed to the rafters.
But organizing committee spokesman Mario Andrada said "We’re not disappointed because we understand that without local heroes and local athletes, some of the local public takes longer to fall in love with track and field." He however pledged fuller evening sessions.