Following a goalless 90 minutes, the tie was decided by penalty kicks, with the home side coming out as 4-3 winners, ensuring their passage into the third round of qualifying for this year's competition.
Tom Gilbert and Tom Cadman returned to Shaun Saunder's starting line-up, giving a powerful and experienced look to the Isthmian South East leaders. Top scorer, Jerson dos Santos, was on a very strong Haywards Heath Town bench.
Having shipped seven goals in each of their last two Isthmian League games, it was no surprise to find Dan Purdue making his debut in goal for the Reds.
The young keeper did himself, and his teammates, proud as he stopped anything and everything that was fired his way.
With Haywards Heath in good form, they started on the front foot, enjoying most possession. Early chances came and went for Gilbert and Gil Carvalho, with Purdue doing well to keep the visitors at bay.
The hosts had a couple of chances of their own through Shakeel Morris and Gio Palmer but Billy Collings, in the Heath goal, wasn't overly troubled throughout the first period and what he did, he did well.
As the half wore on, it was the hosts who started bossing proceedings, gaining in possession and confidence. The tie was finely balanced as the players returned to the changing rooms for a well-earned half-time break and words of wisdom from their respective managers.
Northwood opened the second half the brighter, looking to take the game to their high-flying visitors, but this was countered when Cadman smashed a shot against the bar, on the hour mark.
The hosts hit the woodwork themselves 10 minutes later, as the ever-dangerous Morris fired past Collings, only to hit the upright.
The best chance of the game fell to Luke Robinson, with just five minutes left on the clock. His goalbound header was somehow clawed away by Purdue and the resulting follow up was fired high, wide and not so handsome.
The lottery of penalty kicks followed and whilst Collings saved from Adam Cash, Heath missed with two of their spot kicks, with that man, Purdue, having a debut to remember and the last word, by saving from Cadman.
Blues boss Saunders said: "I am hugely disappointed in the result but not so with the performance.
"Northwood played with great heart and commitment and had an inspired keeper in their side. Congratulations to them.
"We have again travelled to a tough away game and not lost in the 90 mins. I love a good cup run but I am much more concerned with things elsewhere this season. We have other fish to fry.
"We now have a very important run of league fixtures over the next three weeks, so let's see where that takes us."