Kenya’s Lawrence Cherono won a men’s race that came down to the wire in 2:05:45 — barely edging Ethiopia’s Dejene Debela who was second in 2:05:46 with another Ethiopian, Asefa Mengstu, third in 2:05:48.
Last year’s winner Mo Farah of Britain was never a factor — finishing a distant eighth in 2:09:58.
It was a disappointing end for Farah to a week that began amid a hail of questions about the scandal surrounding his former coach Alberto Salazar.
US distance running guru Salazar has been banned for four years by the United States Anti-Doping Agency for a string of doping violations.
Salazar has denied wrongdoing, but Nike shut down its Oregon Project running group headed by Salazar, and four-time Olympic gold medalist Farah arrived in Chicago for his defence to find himself again denying any irregularities during his time with the coach.