Paula Radcliffe holds the key to whether the British selectors send a women's marathon side to compete in August's World Championships in Osaka.
Two years ago, Radcliffe stormed to a convincing victory at the worlds in Helsinki, with her gold-medal placing helping lift the side to bronze position in the team race.
Mara Yamauchi, who along with Hayley Haining was one of the trio in the Finnish capital, clinched an individual slot for Osaka as she finished sixth for the second successive year in the Flora London Marathon.
Japan-based Yamauchi - now a genuine world-class performer - just missed her personal best by 28 seconds when she clocked a time of two hours 25 minutes 41 seconds despite the hot conditions.
Liz Yelling, two places behind her, also achieved the individual qualifier for Japan when she sliced 14 seconds from her previous fastest with a mark of 2hrs 30mins 44secs, while Kathy Butler dropped out after 16 miles.
Radcliffe has not yet committed herself to the marathon in Osaka, although if she was to do so Yelling would be likely to follow suit, with a Great Britain team containing the world record holder in with a chance of a medal in the team event.
Yamauchi, eager to race in Osaka, said: "I'm pleased to have come sixth again because it was a really good field, better than last year and I was pleased to get close to my personal best.
"I was not so pleased to run the whole thing on my own, but I suppose it was good for my discipline," added the 33-year-old Commonwealth Games 10,000m bronze medallist, running alone after only two miles.
Yamauchi said: "I really wanted to do a quick time - about two hours 22 minutes or two hours 23 minutes, and I don't know why I couldn't run quicker.
"I felt quite good in the last 10K and I've no excuses
"I shall have to go away and think how to run a faster marathon - I think that will involve getting my 10k and half-marathon times down."
Despite setting a lifetime best in a race won by China's Chunxiu Zhou by over a minute from Gete Wami of Ethiopia in a world-leading time for the year of 2:20.38, Yelling was unhappy with her display.
She said: "I'm really disappointed - I really thought that I could do sub-two hours 30 minutes.
"I thought that two hours 28 minutes was achievable but I didn't anticipate the weather."
Radcliffe has suffered a minor setback to her summer's preparations while training in the USA and has still to declare which option she will choose.
Meanwhile, Commonwealth bronze medallist Dan Robinson and Andi Jones coped much better than some of their more famous opponents - including Olympic champion Stefano Baldini - to claim exceptional top-10 finishes in the men's race.
They were no match for Martin Lel who, in a thrilling sprint for the line, beat off the challenges of Abderrahim Goumri and defending champion Felix Limo, to regain the title he won two years ago in 2:07.41.
But the pair coped extremely well in the conditions to finish ninth and 10th in times of 2:14.14 and 2:17.49.