Britain's Mara Yamauchi gallantly broke up the field before going backwards herself and finishing ninth in the marathon at the World Championships this morning in Osaka.

Yamauchi then almost immediately suffered for the effort as Catherine Ndereba regained the title she won four years ago in Paris clocking a time of two hours 30minutes 37seconds.

Kenya's former world record holder, beaten for the gold medal in 2005 by Paula Radcliffe in Helsinki, blunted the challenge of world leader Chunxiu Zhou with a breakaway two kilometres from home.

The Chinese winner of the Flora London Marathon in April posted a time of two hours 30min 45secs with Japan's Reiko Tosa third in two hours 30min 55secs. Yamauchi, improving nine places on her finish in Helsinki, clocked a time of two hours 32mins 55secs and was a contender until the 32 kilometres point.

There the 34-year-old Japan-based athlete paid the penalty for reducing the field from 20 to nine being largely responsible for inserting a 17min 40secs split between 25km and 30km.

Yamauchi paid for that decision when her remaining rivals, Ndereba and Zhou, stepped up the pace until the closing stages, content to let others do the work.

"The men's race was decided right at the end so I thought I had to keep something in reserve," said Yamauchi a former foreign office diplomat living in Tokyo with husband Shige.

Yamauchi however, deciding

to change tactics, said: "I thought this is my big chance so I've got to try, but I died a bit after that.

"It didn't hurt that much but before I knew it there was a tiny gap. I didn't panic and thought I could get back on the group. It didn't get bigger for quite a while.

"I felt people would come back to me and kept telling myself: 'Don't settle for ninth they might come back to me over the next 10km.

"I tried to stay strong to the end but the gap was becoming bigger."

Tracey Morris, after knee surgery and other injury problems earlier this year, finished 19th in a time of two hours 36min 40secs.

"I tried to put it all into this one day," said Morris, who emerged to stardom four years ago at the London marathon when clinching an Olympic place as the first Briton across the line in the trial race.

Morris, who suffered another fall and damaged her right knee training in Macau three weeks ago, set off at her own planned pace, but although in no-mans land at times on her own, comfortably finished the race.