Keitany, 34, ran a time of two hours 24 minutes 26 seconds to become the first to accomplish the feat since Norway’s Grete Waitz – who won five in a row.
Ghebreslassie, who finished fourth at both the London Marathon and the Rio Olympics this year, crossed the line in 2:07:51 to deny Kenya a fourth consecutive double in the New York men’s and women’s races.
“I am really proud with my victory today to be the first one from my country [to win the race],” he said.
American Tatyana McFadden won her fourth straight New York women’s wheelchair race in one hour 47 minutes 43 seconds.
The win means she has won the last 17 major marathon races – London, Boston, Chicago and New York – including four calendar-year clean sweeps.