Okayo won the race for the second time and shattered her own record for the 26.2-mile course with a time of 2:22:31. She broke her own mark of 2:24:21, set in 2001, by 1 minute, 50 seconds.
The win earned her $160,000.
Lel passed 2002 winner Rodgers Rop with one mile to go and pulled away on Central Park South to win the men's run with a time of 2:10:30. Rop was second and Christopher Cheboiboch third for the second straight Kenyan sweep of the top three spots.
Lel also won the world half-marathon title in 1:00.49 in October. His personal-best was 2:10:02 in the Venice Marathon last year.
Kenyan-born women took the three top spots as world champion Catherine Ndereba was second in 2:23:04 and Lornah Kiplagat, who became a Dutch citizen recently, was third at 2:23:43.