The only goal of the game came in the 6th minutes as Michael Wood shot through a body of players and into the far corner following a lay off from Cecil Jee.
With the exception of Wood’s early strike, the first 45 minutes was largely forgetful but the second 45 saw James Broadbent forced into a number of fine saves to keep Loxwood at bay.
A counter attack ended at the feet of Sam Beard who was denied by Broadbent before the United ‘keeper produced a point blank save to thwart Loxwood skipper Eddie French.
Ross Swaine was next to find Broadbent in fine form as his low effort was tipped wide.
United had claims for a penalty turned away as French used his strength to outmuscle Aaron Filsell in the area before Broadbent saved again from Beard.
United’s best chance of the evening fell to the prolific Liam Baitup, but the United marksman fired a left footed effort over the bar late on as Loxwood progressed to the last eight and a home fixture against Horsham.