By Peter Rutherford
Kirui's gold medal was the seventh of the championships for Kenya, who swept the podium in the women's marathon.
Kirui, who now has the two fastest times in the men's marathon at the world championships after he set the record of 2:06:54 in Berlin, was not even included on Kenya's provisional list for Daegu.
"They made a wise choice to recognize me," Kirui said with a smile.
But such is Kenya's depth of distance running talent, he does not know whether it will be enough to earn him a spot at the 2012 Olympics.
"I hope I have an automatic ticket now but only the coach will know," he added.
After a cagey opening, Kirui made the decisive break around 33km, a sustained burst of pace taking him clear of Lilesa and Kipruto as the crowds lining the streets of downtown Daegu cheered him on.
It was a risk to strike out for home with almost 10km left to run, but Kirui said his mind had told him to go and that it was a good strategy given the quality of opposition at his shoulder.
"When it comes to a race with strong competitors, you also need to be wise," he added. "It's not all about your legs -- it's a lot to do with the mind too."
Crossing the line with fingers pointing to the sky Kirui still had the energy to hop around in a victory dance, then respectfully moved to the side to await the arrival of his compatriot Kipruto.
"I was so glad," he said of his dance at the finish line. "It was emotional, I found myself dancing and rejoicing."
(Editing by Alastair Himmer)