United were unchanged from the side that had defeated Loxwood a little over 48 hours previously, but the performance was that of a side that had only just met.
From the first whistle, United struggled to gain a foothold in the game and were second best throughout and were deservedly beaten.
James Broadbent reacted well with his feet to thwart Rory Biggs early on before United talisman Liam Baitup fired over at the other end following an enticing through ball from Chamberlain.
With less than a quarter of the match played, United found themselves a goal down as a long range effort from Biggs could only be parried by Broadbent into the path of the onrushing Asa Nicholson who found the back of the net.
Josh Biggs saw an effort for the home side saved by Broadbent before going even closer as he struck the bar with the United ‘keeper beaten.
The closest United came to fashioning an opening was through Tom Saunders, but the striker saw his effort from the edge of the area curl wide of the far post.
The half-time team talk appeared to have worked on the United side as they came out with a renewed vigour and two minutes into the half were rewarded as Jamie Bunn’s whipped cross was glanced in at the near post by Chamberlain.
Less than two minutes after drawing level, United were inches away from falling back behind as Josh Biggs managed to breach the United defence, but lifted his effort over an onrushing Broadbent which bounced just past the outside of the post.
With little over ten minutes remaining, United found themselves temporarily down to ten men as Dave Smart received treatment for an injury that would see him substituted minutes later, the home side made there brief numerical advantage count as Jordan Jones outmuscled Pete Featherstone before centring the ball to Max Thoms who slammed the ball past Broadbent.
Five minutes later, the game was put out of United’s reach as Aaron Hooker-Meehan squared the ball to Thoms to make it three, before United’s miserable evening in West Sussex was compounded on the stroke of full time when Dave Herbert saw an effort find the back of the net despite the best efforts of Broadbent to complete the scoring