Jo Pavey produced another gutsy display to finish ninth in the 5000m final in a season's best 15:04.77, a week after agonisingly finishing fourth in the 10,000m final.
Pavey has decided to concentrate on the longer event this year, but the Commonwealth Games 5000m silver medallist insisted she was not going to pass up the opportunity to run in a World Championship final.
"I am disappointed," said Pavey. "I didn't feel that good before the race, I wasn't injured and that's why I wanted to give it a go. When I was warming up I knew it was going to be a bad day after doing the 10k and then the five, it was putting damage on top of damage. I struggled with the recovery, but I wanted to give it a go.
"I feel like I have made the wrong decision because I didn't produce a performance, but it is a World Championship final. If I hadn't tried I would have been left thinking 'what if' for the rest of my life.
"I know I have made the wrong decision having a go, but I know I have made the right decision because I will be not left wondering.
"The 10 was always the priority and I was only doing the five if I was not injured and wanted to give it a go. I was pleased with the way the 10 went because that is the event I want to do at the Olympics."
The gold medal went to Meseret Defar of Ethiopia in a time of 14:57.91secs.
The 2004 Olympic champion easily outpaced the Kenyan pair of Vivian Cheruiyot and Priscah Cherono who clocked 14:58.50 and 14:59.21 respectively.
It was the second slowest time since the distance replaced the 3,000m in the championship schedule 12 years ago.
"I had only one goal today at my third world championships and I wanted the gold medal," said Defar, who failed to make the final on her debut four years ago in Paris.
The 23-year-old African added: "Finally I'm world champion. My tactics were to wait until the last two laps and then start my finish.
"In the last lap I controlled the situation in the first 200m and then started to kick."
Defar, who contested her heat with a stomach upset, revealing she will defend her Olympic crown added: "I am the champion and that is great.
"In Beijing I will run the 5,000m and maybe in the future try 10,000m."