CHICAGO — Dennis Kimetto and Rita Jeptoo led a Kenyan sweep in contrasting styles at the Chicago marathon Sunday in a race staged amid heightened security after the Boston marathon bombings in April which killed three people. Kimetto won the men's race after a gripping duel with compatriot Emmanuel Mutai while Jeptoo cruised to an easy victory to add the Chicago women's crown to the Boston title she won this year. Taking advantage of ideal conditions, Kimetto covered the 42.195 kilometers (26 miles and 385 yards) in two hours three minutes 45 seconds to shatter the course record of 2.04:38 set last year by Ethiopia's Tsegaye Kebede. Pushed by Mutai, Kimetto had been on world record pace over the closing kilometres but fell short of Wilson Kipsang's mark of 2:03:23 set in Berlin this year. Kimetto was followed across the line by Mutai, who also broke the course record, while Sammy Kitwara finished third as Kenyans dominated the race by sweeping the top four positions. “I am happy because I set a course record,” said KimettoJeptoo, who also won the Boston marathon in 2006, showed her class by pulling away from the elite field and smiling and waving to the massive crowd as she completed the route through the Windy City neighborhoods in a time of 2:19.57, the fastest by a woman this year. Jemima Sumgong Jelegat came home a distant second 53 seconds behind the winner with Russia's Maria Konovalova taking third to prevent another Kenyan podium sweep. — Reuters