Chicago - Two-time world champion Abel Kirui filled a gap on his resume, denying Dickson Chumba a second straight Chicago Marathon title and winning his first World Major Marathon race.
Kirui, who has battled a litany of injuries since winning silver at the 2012 London Olympics, clocked 2hrs 11min 23sec with Chumba second in 2:11:26 and Gideon Kipketer third in 2:12:20.
"I was putting in my prayers and efforts in winning today," said 34-year-old Kirui. "I had a very strong mind, this time I knew it was a matter of life and death. The course favored me and I was lucky that the weather was not so humid."
While Chumba was unable to repeat his 2015 triumph, Kenya's Florence Kiplagat won her second straight Chicago crown, powering to a dominant victory in 2:21:32, almost two minutes ahead of runner-up Edna Kiplagat's 2:23:28.
Valentine Kipketer, sister of Gideon, completed the Kenyan women's sweep, finishing third in 2:23:41.
In a men's race that in the absence of a pace-setter featured erratic surges in speed, a trio of Kenyans, Chumba, Kipketer and Kirui, broke away late from a group of 13.
With two kilometers remaining Chumba and Kirui had separated themselves and were jockeying for the lead before Kirui, running in Chicago for the first time, made a decisive move.
"It's wonderful, amazing," said Kirui, who was embraced by training partner Kiplagat after the women's winner crossed the finish line.
Her dominant display ensured there was no finish-line drama in the women's race, in which a tight-knit leading group set a more methodical pace through the first two-thirds of the race than the top men managed.
The half-marathon world record-holder powered home all alone, giving a quick victory dance after crossing the line.
"When I was coming here I was determined to win because I just wanted to win twice," said the Kiplagat, who didn't approach her personal best of 2:19:44 set in Berlin in 2011 but who bettered the 2:23:33 she ran in Chicago last year.
Kirui, world champion in 2009 and 2011, said he now wants to tackle the London marathon, and take on top marathoners Eliud Kipchoge, Kenenisa Bekele and Wilson Kipsang.
Bekele missed the world record by six seconds in winning in Berlin last month, ahead of Kipsang.
"I was praying so hard that I get something here so that I request my manager to give me the three guys: Eliud, Bekele and Wilson Kipsang," Kirui said.
Paul Lonyangata and Stephen Sambu completed an all-Kenyan top five in the men's race, Sambu making his marathon debut after establishing himself in shorter-distance road races since graduating from the University of Arizona in 2012.