The 90-year-old man was struck at the intersection of Metropolitan Avenue and Orient Avenue just after 11:30 a.m.
He was rushed to Bellevue Hospital in critical condition.
The vehicle, a white food services truck, fled the scene.
But the driver was chased down by a Good Samaritan and police, who stopped the truck blocks away at the intersection of Meeker Avenue and Lorimer Street.
47-year-old Hernan Diaz was arrested and charged with vehicular assault, leaving the scene of an accident, and DWI.