Jordan Maguire-Drew nearly put the Daggers in front early on when he struck the woodwork while at the other end, Ryan Bird did the same with a header as the sides sparred.
In the second half, Matt Robinson threaded a through-pass to Whitely, who controlled and dispatched under Ryan Clarke with the confidence of a striker - a goal that ended an impressive 10-match unbeaten run for the hosts.
Whitely could have put a greater gloss on matters for John Still's side, but he struck the bar from 20 yards.
Report supplied by the Press Association.
Match ends, Eastleigh 0, Dagenham and Redbridge 1.
Second Half ends, Eastleigh 0, Dagenham and Redbridge 1.
Substitution, Eastleigh. James Constable replaces Ryan Bird.
Substitution, Eastleigh. Jamie Cureton replaces Adam Dawson.
Frankie Raymond (Dagenham and Redbridge) is shown the yellow card.
Substitution, Eastleigh. James Granger replaces Adam Dugdale.
Goal!  Eastleigh 0, Dagenham and Redbridge 1. Corey Whitely (Dagenham and Redbridge).
Substitution, Dagenham and Redbridge. Fejiri Okenabirhie replaces Sam Ling.
Second Half begins Eastleigh 0, Dagenham and Redbridge 0.
First Half ends, Eastleigh 0, Dagenham and Redbridge 0.
Matt Robinson (Dagenham and Redbridge) is shown the yellow card.
First Half begins.
Lineups are announced and players are warming up.
Corey Whitely took Dagenham to second place in the National League with the only goal in their win away at Eastleigh.