Two-time world champion and 2012 Olympic silver medallist Abel Kirui won the Chicago Marathon on Sunday in 2hrs 11min 23sec as Kenyans swept the men's and women's races.
Countrywoman Florence Kiplagat defended her women's title, winning by almost two minutes.
Kirui, a former two-time world champion, won in two hours, 11 minutes and 23 seconds.
Countyman Chumba, who only arrived in Chicago on Friday after visa problems, was three seconds back.
Third went to Kenyan Gideon Kipketer.
Kiplagat broke away after 30 kilometers in the women's race and was never challenged, winning in 2:21:32.
Compatriot Edna Kiplagat took second in 2:23:28 and another Kenyan, Valentine Kipketer, was third.
Results from the World Marathon Majors Chicago marathon Men ::
1. Abel Kirui (Kenya) 2:11:23
2. Dickson Chumba (Kenya) 2:11:26
3. Gideon Kipkemoi Kipketer (Kenya) 2:12:20
4. Paul Lonyangata (Kenya) 2:13:17
5. Stephen Sambu (Kenya) 2:13:35
6. Abayneh Ayele (Ethiopia) 2:13:52
7. Takuya Fukatsu (Japan) 2:13:53
8. Diego Estrada (U.S.) 2:13:56
9. Koji Gokaya (Japan) 2:14:34
10. Elkanah Kibet (U.S.) 2:16:37
Results from the World Marathon Majors Chicago marathon Women ::
1. Florence Kiplagat (Kenya) 2:21:32
2. Edna Kiplagat (Kenya) 2:23:28
3. Valentine Jepkorir Kipketer (Kenya) 2:23:41
4. Purity Rionoripo (Kenya) 2:24:47
5. Yebrqual Melese (Ethiopia) 2:24:49
6. Atsede Baysa (Ethiopia) 2:28:53
7. Serena Burla (U.S.) 2:30:40
8. Agnieszka Mierzejewska (Poland) 2:32:13
9. Sarah Crouch (U.S.) 2:33:48
10. Alia Gray (U.S.) 2:34:00