The match was played in abhorrent conditions, with torrential rain and a strong wind battering The Oval prior to the start of the match.
It was Lancing who adapted to the tricky conditions the better, with Alex Fair seeing a free kick tipped over by Callum Christie before Christie produced an even better save to deny Callum McHale as he dived full length to thwart a goalbound header
Christie found himself penalised for holding on to the ball for too long before a goal kick and conceded an indirect free-kick, but United captain Adam Davidson put his body on the line to block a strong effort.
A brief flashpoint came with ten minutes of the half remaining as Liam Painter found himself on the end of a strong challenge, with players from both sides coming together before order was resumed by the match official.
United’s only chance of the half fell to Liam Baitup, but the strikers pot shot failed to test Lancing ‘keeper Fidler.
The half-time whistle was met by another torrential downpour with supporters scurrying for cover.
The second half carried on in much the same vein of the first, with Lancing controlling the game and seven minutes into the half they took the lead as Fair struck an effort across Christie.
With time running out, United began to push bodies forward and were punished as Jared Rance capitalised on a slip by Liridon Morina to slam home the ball past Christie and seal the victory