Claire Hallissey looks set to claim the last available marathon place in the Olympics after finishing 11th in the Virgin London Marathon.
Hallissey's time of two hours 27 minutes 44 seconds was 40 seconds quicker than the time run by compatriot Jo Pavey in last year's race, putting Hallissey in pole position for the final Olympic place available alongside Paula Radcliffe and Mara Yamauchi.
Scotland's Freya Murray also ran under Pavey's time in finishing 13th in 2hrs 28mins 10secs, meaning Pavey's gamble of not running in London appears to have backfired ahead of Monday's team announcement.
A delighted Hallissey, 29, said: "I just really enjoyed it and everything seemed to click into place. It's always difficult in the marathon, you can never tell until you get near the finish if you are going to maintain the pace. It was the fastest I have ever gone out and I could feel the extra pace and it did hurt.
"There was no point just turning up and running a conservative race and trying to get a slight personal best. It was all or nothing. I have done everything I came here to do but it's in the selectors' hands. It would be fantastic (to be picked). A home Olympics is a chance of a lifetime."
Pavey was quick to congratulate her rivals, saying it was not "all doom and gloom" for her. "Congratulations to them both and especially Claire coming in first Briton. She ran so well," Pavey said.
"I have to sit and wait. There is a chance that they (the selectors) might take into account I ran a good time in New York on a hilly course but I think that won't be the case. I am not holding my hopes up for that. I'll turn my attention to trying to qualify on the track."
Kenya's Mary Keitany retained her title with a time of 2:18.37 - a new personal best and the fourth fastest ever in London - with compatriots Edna Kiplagat and Priscah Jeptoo second and third respectively.
In the men's race, Wilson Kipsang made it a Kenyan double with victory in 2:04.44, just four seconds outside the course record set last year by Emmanuel Mutai.
Lee Merrien was the first British man across the line in 17th, but his time of 2:13.41 was outside the Olympic 'A' standard of 2:12.00. Scott Overall, who is the only British man qualified for the Olympics after finishing fifth in Berlin last year, was acting as a pacemaker but dropped out with a minor hamstring strain.