The two were neck-and-neck for much of the race before Kimetto pulled way in the closing stages to win the first major US marathon since the bombings at the Boston Marathon in April killed three people.
Kimetto beat the course record of 2:04:38 set by Ethiopian Tsegaye Kebede last year and added the Chicago title to the Tokyo Marathon crown he won in February.
Kenya’s Rita Jeptoo won the women’s race in an unofficial time of 2hr 19min 57sec.
While security was on the minds of many runners during their 26.2 mile journey through the city’s streets, runners didn’t let it stop them as the winning runners set a new course record in what has become a historic Chicago Marathon.
Kimetto’s time was the fourth fastest ever, missing by 22 seconds the world record Wilson Kipsang of Kenya set in Berlin two week ago.
Dathan Ritzenheim (fifth) was the top US finisher in 2:09:47.
Rita Jeptoo of Kenya won the women’s title Sunday in an official time of 2:19:57.
Jeptoo was coming off a Boston Marathon victory in 2:26:25.
Ernst Van Dyk of South Africa made a pass in the final 10 meters to beat 4-time winner Kurt Fearnley of Australia by one second in the men’s wheelchair race. Josh George of Champaign, a 3-time winner, also was 1 second behind. Winning time was 1 hour, 30 minutes, 37 seconds.
It was 53 degres with almost no wind 30 minutes before race time.
There was just a 30-second moment of silence to honor the victims of the bombing at the Boston Marathon.