Chicago - Dennis Kimetto out-dueled fellow Kenyan Emmanuel Mutai in the final mile on Sunday to win the Chicago Marathon in a course record of 2 hours, 3 minutes 45 seconds.
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.
Kimetto flirted with but ultimately fell short of the world record of 2:03:23 set by Wilson Kipsang in Berlin last month, but he was pleased to claim the Chicago course mark and a $75 000 bonus that came with it.
"I am happy because I set a course record," he said. "The conditions were very good."
It marked the third straight year a course record was set in Chicago.
Kenyan Moses Mosop had clocked a record of 2:05:37 in 2011, but settled for eighth place on Sunday.
Mutai was second in 2:03:52 and two more Kenyans, Sammy Kitwara and Micah Kogo rounded out the top four, with American Dathan Ritzenhein fifth.
Rita Jeptoo continued Kenya's dominance with a victory in the women's race in 2hr 19min 57sec.
Jeptoo erased the bitter memory of her one-second loss to Ethiopian Atsede Baysa last year, and while she had the victory in hand pushed herself at the end to break the 2:20 mark.
"I feel good, I'm happy," said Jeptoo, whose time was the fastest by a woman this year.
"This year I trained very, very good because I was training with a new coach. I was not 100 percent thinking I am going to win but because of training I believe I ran good."
She was comfortably in front of compatriot Jemima Sumgong Jelegat, who finished second in 2:20:48. Russian Maria Konovalova was third, ahead of Aliaksandra Duliba of Belarus and Baysa.
Jeptoo claimed her second major US title of 2013. She had already wrapped up victory in Boston and received her prize when two bombs went off near the finish line, killing three and injuring some 200 people.
One suspect in the attack, Tamerlan Tsarnaev was later killed during a shootout with police, while his younger brother Dzhokhar Tsarnaev has pleaded not guilty to 30 charges, 17 of which are punishable by death.
A moment of silence in memory of the Boston attacks was held at the start in Chicago, where organizers beefed up security procedures.
For the first time, access to the finish area required a ticket, and a massive police presence reassured fans and family members that everything that could be had been done to protect some 40,000 runners and more than a million fans expected along the 26.2 mile course.
1. Dennis Kimetto (Kenya) 2:03:45
2. Emmanuel Kipchirchir Mutai (Kenya) 2:03:52
3. Sammy Kitwara (Kenya) 2:05:16
4. Micah Kogo (Kenya) 2:06:56
5. Dathan Ritzenhein (USA) 2:09:45
6. Ayele Abshero (Ethiopia) 2:10:10
7. Hiroaki Sano (Japan) 2:10:29
8. Moses Mosop (Kenya) 2:11:19
9. Yoshinori Oda (Japan) 2:11:29
10. Matthew Tegenkamp (USA) 2:12:28
1. Rita Jeptoo (Kenya) 2:19:57
2. Jemima Jelagat Sumgong (Kenya) 2:20:48
3. Mariya Konovalova (Russia) 2:22:46
4. Aliaksandra Duliba (Belarus) 2:23:44
5. Atsede Baysa (Ethiopia) 2:26:42
6. Ehitu Kiros (Ethiopia) 2:27:42
7. Yukiko Akaba (Japan) 2:27:49
8. Abebech Afework (Ethiopia) 2:28:38
9. Clara Santucci (USA) 2:31:39
10. Melissa White (USA) 2:32:37