This wasn’t quite as one-sided as the scoreline might suggest, as the Stringers more then held their own in the first half before Down capitalised on their opponents’ tired legs in the last 20 minutes.
Anvils made three changes from the disappointing result last Tuesday night, with Tom Gannon starting up front in place of Sam Cane, and Williams Peauroux and Sonny Barton replacing the absent Marc Pelling and Michael Belli.
Crawley Down’s opener came after Oli Leslie had been felled outside the box, with Sullivan’s free-kick being nodded home by Mike Spence past Stringers keeper Tom Bradford.
More was to come on 18 minutes when from an Anvil clearence, Leslie was able to evade centre-back Jack Findon and slide the ball past Bradford to give the Anvils a two-goal lead.
The Stringers then started to make movements of their own, with Charlie Shearing taking advantage of a Blair Cooney slip but shooting well wide.
On 20 minutes there was a Dave Chan attempt straight at Anvil keeper Martin Hopkins.
They continued to push forward, with shots from Simon Piper and a header from Shearing, but overall they were not really seriously testing the Anvil backline.
Gannon had another shot blocked, but perhaps the most notable part of the first half came just before half-time with full-back Sonny Barton from around 35 yards, releasing a rocket of a shot that flew past the far upright.
Crawley Down went 2-0 up ten minutes into the second half when Jack Findon slid the ball past Bradford.
A combination of Spence and Leslie caused a scramble in the box that led to Thomas scuffing his shot home for a 3-0 lead.
Within minutes of coming on, Sam Cane was on hand to notch a quickfire double and put the Anvils 5-0 to the good.
The Stringers were now noticeably tiring with the relentless Anvil pressure but were still making the odd sortie, with a Ross Markham shot taken by Hopkins, and Connor Townsend shooting wide.
With the Anvils now pouring forward, it was just a case of how many, with continuous balls pumped forward. Everyone seemed to be eager to get on the scoresheet, with a Williams Peauroux corner being headed over by James Day.
A Cooney charge down the flank was rewarded on 87 by another Spence finish, to give the midfielder a well-deserved double season.
To round off proceedings leading marksman Leslie applied that well-known coup de grace with the seventh of the match, and three more points that saw the Anvils reached 52 points for the season.
Crawley Down Gatwick: Hopkins, Martin (White), Barton, Day, Cooney, Peauroux, Sullivan (Goodwin), Spence, Gannon (Cane), Leslie, Thomas
Man of the Match: