Kenyan Dennis Kimetto repulsed a challenge from compatriot Emmanuel Mutai to win the Chicago marathon in a course record time yesterday.

Taking advantage of ideal conditions, Kimetto covered the 42.195 kilometres in a time of two hours three minutes 45 seconds to shatter the course record of 2.04:38 set last year by Ethiopia’s Tsegaye Kebede.

Kimetto was on world record pace throughout the final kilometres while Mutai crossed eight seconds behind, also smashing the old course record in 2:03.53.

In the women’s race, Kenya’s Rita Jeptoo completed a dazzling double by cruising to victory in Chicago after winning in Boston earlier in the year.

Jeptoo showed her class by pulling away from the elite field and smiling and waving to the massive crowd as she ran the distance through the Windy City in two hours 19 minutes 57 seconds.

Her compatriot Jemima Sumgong Jelegat came home a distant second in 2:20.57.

Security was increased for the race, which attracted 40,000 runners, after the Boston marathon bombings in April which killed three people.