Dibaba beat Meseret Defar's time set in the same stadium last year
Ethiopian Tirunesh Dibaba set a new world record in the women's 5,000m at the Oslo Golden League meeting.
The 22-year-old crossed the finishing line in a time of 14 minutes 11.15 seconds, breaking compatriot Meseret Defar's previous mark by 5.48 seconds.
The world 10,000m champion's sister Ejegayehu Dibaba finished third, with Kenya's Lucy Wangui taking second.
Britain's Jo Pavey finished well under the Olympic qualifying standard in eighth place.
Although she was never in contention in the race, the Commonwealth silver medallist finished in a time of 15:02.41 seconds, which could persuade the selectors to choose her for both the 5,000m and 10,000m in Beijing.
Elsewhere, England's Andy Baddeley stunned his predominantly African rivals by winning the 'Dream Mile' with a late sprint, setting a new personal best in the process.
The 25-year-old, who finished third in last year's race, was rewarded with a time of 3:49.38 and became the UK's first winner of the race since Peter Elliott in 1991.
"This is a big breakthrough for me taking seconds from my previous best," said Baddeley. "My coach told me after I had run so well last year that I could run under 3 minutes 50 seconds.
"Let's remember all these races I've got planned are in preparation for August and the Olympics. This was a good start."
Baddeley admitted Tom Lancashire's victory in the 1500m had also pressurised him with European Cup selection looming on the horizon.
"It made me more aware of what I had to do, but it's great to see such a resurgence in British middle distance running," he said.
Marlon Devonish finished fourth in the 100m with a wind-assisted time of 10.08 seconds but was realistic enough to know his hopes of running over the distance at the European Cup are unlikely to be realised.
Tyrone Edgar's legal mark of 10.06 seconds in Geneva last Saturday is likely to give the US-based sprinter the position in the side for the meeting in Annecy in a fortnight's time.
Baddeley set a personal best time of 3 minutes 49.38 seconds
But Devonish stated his credentials to defend the 200m title he won a year ago in Munich by clocking 20.59 seconds for fifth in the 200m - the fastest by a Briton this summer.
Now the selectors have to make the decision whether to choose the European bronze medallist or Christian Malcolm, who won in Geneva with 20.70sec, when picking the team on Monday.
World 400m champion Christine Ohuruogu moved into new territory by beating the 23 second mark over 200m for the first time with an excellent third in her race.
Ohuruogu, who makes her one lap debut for the season in Ostrava next Thursday, clocked 22.94 seconds as Bianca Knight of the USA won in 22.56 seconds, ahead of Russia's Yuliya Guschina.