Ivuti’s sedate winning time of two hours 11min 11sec, almost seven minutes outside last Sunday’s world record set by Haile Gebreselassie in Berlin, was blamed on the 25 degree heat and 86% humidity.
Ivuti was able to celebrate the victory after awaiting a photo that determined the winner.
Ivuti became the sixth consecutive Kenyan to triumph in Chicago, one of the world’s five ‘majors’ alongside Berlin, London, New York and Boston.
The women’s race was won by Ethiopia’s Berhane Adere, the 2006 winner, from Romania’s Adriana Pirtea in second.
It was over another minute back to Daniel Njenga, who finished third. The Kenyan was second here last year.
There was even more drama on the women’s side where Adere finished just three-tenths of a second in front of Adrianna Pirtea of Romania.
Adere won in dramatic fashion, sprinting past Pirtea in the final 15 yards to hit the tape first with a time of 2:33.49. Kate O’Neill of the United States was third.
Britain’s Liz Yelling, finished fourth with a time of 2:37.14.
The unseasonable heat and humidity prompted organisers to close the course at the halfway point at noon, ending the day for any of the non-elite runners who hadn’t made it to the midpoint of the race, in which 36,000 people started.