Five-time Olympian Jo Pavey missed a chance to qualify for the World Championships in London after finishing fourth in the British 10,000m trials.
Rio 2016 Olympian Beth Potter, 25, booked her place by winning the Night of 10,000m PBs event in Hampstead in a time of 32 minutes four seconds.
Pavey, 43, who needed to claim a top-two finish, clocked 32:43.
Andy Vernon won the men’s event with a time of 28:21 but fell short of the 27:45 required to reach the Worlds.
Vernon, a 10,000m silver medallist at the 2014 European Championships, could afford to high-five spectators during the final lap as the 31-year-old finished 11 seconds ahead of Dewi Griffiths in second.
The top two in the men’s and women’s trial events could secure their spot on the GB team provided they have also achieved the qualification time, with a deadline of 9 July to reach the standard.
Women’s runner-up Steph Twell, 27, agonisingly missed out on the required mark of 32:15 with a time of 32:16.23 on her 10,000m track debut.
Pavey, who finished behind third-placed Katrina Wootton, decided to concentrate on track racing after failing to finish the London Marathon last month.
Her best effort at the World Championships was bronze in the 2007 event, although she only inherited the medal earlier this year after Turkey’s Elvan Abeylegesse was retrospectively disqualified for a doping offence.