The event in the Windy City took place amid tightened security following the bombings that marred the Boston race in April, in which three people were killed, but it was the action on the roads that thankfully made the headlines this time around.

Just as in Berlin two weeks ago, the men's race was dominated by Kenyans with Kimetto finishing ahead of compatriots Emmanuel Mutai and Sammy Kitwara while Jeptoo and Jemima Sumgong Jelegat completed a Kenyan one-two in the women's event, with Russian Maria Konovalova taking third spot.

Pacemakers Belete Assefa of Ethiopia and Abdellah Falil of Morocco ensured that the first half of the race was not far off world record pace under blue skies in Chicago and as the field slowly began to drop away, Micah Kogo joined Kimetto, Mutai and Kitwara in an all Kenyan leading group at the 35 kilometre mark.

However, Kimetto and Mutai decided the time was right to up the pace and both athletes pulled away in the closing kilometres to set up a straight shoot-out to the line and it was the man who won in Tokyo earlier this year who had the stronger finish as he crossed the line in a time of 2 hours 3min 45sec to shatter the course record of 2:04:38 set last year by Ethiopia's Tsegaye Kebede.

Mutai's time of 2:03:52 saw the 2011 London Marathon winner also break the previous course record in Chicago and register a personal best.

Dennis Kimetto lead home a Kenyan top three in Chicago setting a course record time of 2:03:45