The Hawks now progress to the FA Trophy Second Round Qualifying, banking £3,250 in prize money in the process.
Harlow Town boss Danny Chapman named all four new signings in the match-day squad, with Matt Foy and Tom Hitchcock leading the attack in the starting line-up and Bill Plumpton and Mayowa Adaje named on the bench.
The hosts went ahead mid-way through the first half through Anesu Sisimayi, and it looked as though Harlow Town would struggle again as they failed to create significant chances.
Chapman changed things up in the second half, bringing striker Emile Acquah on for defender JJ Da Cruz and moving to a 3-4-3 formation, and it paid dividends immediately as the Hawks went on the front foot.
The equaliser came in the 66th minute. Whitehawk goalkeeper Melvin Minter dived to his right to keep out a low shot, but he was unable to hold onto the ball and Tom Hitchcock pounced on the rebound from close range to open his scoring tally on his debut.
The hosts reacted quickly and almost went ahead again a minute later. Richard Hayward in the Harlow net made a good save, and although the rebound was followed up into the goal, it was ruled out for offside.
In the 70th minute Harlow Town went ahead. Hitchcock was the instigator this time, and when his shot from outside the area was deflected kindly into the path of Nathan Koranteng, the winger composed himself before slotting it through the legs of the onrushing goalkeeper.
With six minutes of normal time to go, Harlow seemed to have wrapped up the game. A neat ball over the top of the Whitehawk defence from Louis Yuill was brought down nicely by Emile Acquah. He turned well to evade a defender before finishing well to open up a two goal cushion.
Whitehawk weren’t finished yet, and they reduced the deficit to one only two minutes later. A cross was played in to the back post, and Ed Sanders slid into turn it home and give his side hope of earning the replay.
It wasn’t to be however, as Harlow Town saw out the remainder of the game to secure their first win in five games and book their place in the next round of the Trophy.
Full Time: Whitehawk 2-3 Harlow Town
The Hawks will find out their opponents when the draw is made on Monday 29th October, with the game to be played on Saturday 10th November. As a result, the league tie away to Wingate & Finchley that was originally scheduled to be played on that date has been postponed.