Edna Kiplagat, two-time reigning world champion, made up for the disappointment of finishing runner-up for the past two years in London to win in two hours, 20 minutes and 21 seconds, with her namesake three seconds further back.
After breaking away from the field, the pair remained close together until the final bend when Edna Kiplagat surged ahead.
Florence Kiplagat could not respond and Edna Kiplagat broke the finish line tape several yards in front.
Ethiopia’s Tirunesh Dibaba, the Olympic and world 10,000 metres champion, marked her marathon debut by finishing in third place.
She had looked set to challenge the Kenyan duo for much of the race but paid a heavy price for dropping a water bottle and stopping to pick it up. Dibaba finished 14 seconds adrift.
In the women’s wheelchair race, Tatyana McFadden of the United States successfully defended her title just a month after winning a cross-country skiing silver medal at the Winter Paralympics in Sochi.
The 24-year-old won in a course record 1:45:11, more than a minute-and-a half clear of Swiss runner-up Manuela Schar.