The 28-year-old was beaten in the final of the longer event a week earlier but returned to the track yesterday to ensure Team GB’s campaign finished with a flourish.
Farah, who got his tactics spot on in what was a slow run race, held off a late challenge from American Bernard Lagat to win in a time of 13 minutes 23.36 seconds and become the first British male to win a world title over 5,000m.
“I’m very proud. I can’t believe it. It just hasn’t sunk in right now. I came so close in the 10k and I just wanted to do it in the 5k,” he said.
“My coach told me ‘Do not let anyone pass’. I just had to go out there and try to relax; just do what I did in the 10k but get it right this time.
“But you can’t get carried away. It’s a long way [to the London 2012 Olympics]. The aim is to stay injury free. Anything can happen in long distance.”
Farah, who won 10 consecutive races earlier this year after moving his wife and daughter with him to work with his coach Alberto Salazar in Oregon, added: “I just want to thank everyone who’s helped me.
“I’ve made a lot of sacrifices, moving away from home where it’s comfortable relative to everything else and I’m glad I made that choice because it’s working. I’ve got the gold now. It just feels amazing.”
Farah represents Britain’s prime hope of a gold medal at next year’s London Games, but triple jumper Phillips Idowu will head into the Olympics having been dethroned as world champion by Christian Taylor.
The 32-year-old had looked set to retain his title after a season’s best 17.70m restored his healthy lead in the third round. But his American rival then produced a stunning leap of 17.96m to relegate Idowu to the silver medal position.
Team GB finished with eight medals, one more than had been predicted by UK Athletics head coach Charles van Commenee, and the Dutchman declared himself more than satisfied with the performance of his squad.
“That is one of the very best performances we’ve ever had in the history of British athletics,” he said.
“That sets us up with a nice platform for next year, when the target is eight, so it’s my job to find another medal.”