Matt Russell plundered another two goals as Sussex kept their feet on the Lancing Ice.
The Horsham YMCA marksman's second-half brace on top of Gavin Geddes's first half double secured a comfortable win.
Victory at Aldershot against Army FC on Tuesday, February 8, will take the county's rep side through to the South-West Counties Championships final.
And Russell said afterwards "It was always going to be hard on that hard surface.
"Thankfully the pitch held up and we put in a good performance. The boys just need to focus on getting that extra win."
Referee Phillip Owens managed to get the Group C game finished despite the freezing conditions at Colver Road.
Sussex held the initiative with a two-goal lead after an even first half.
Geddes broke the deadlock after ten minutes with a fine solo run and shot across diving Royal Navy keeper Stuart Adams.
Daren Pearce was unfortunate not to double the lead midway through the half when seeing his 20-yard shot hit the inside of the left post and roll across goal.
But the advantage was extended on the stroke of half time when Geddes pounced on a loose ball after Adams failed to hold John Snelgrove's effort from the left edge of the box.
Russell made it three with a low clinical finish 15 minutes after the re-start.
Then the 20-year-old striker added a fourth seven minutes later when one-on-one with the keeper to fill victory.
Sussex: Chatfield (Redhill), Baker (Langney Sports), Willard (Langney Sports), Dodden (Sidley United), Austin (Eastbourne Town), Smart (Horsham), Lovett (Crawley/sub Lutwyche, Burgess Hill 68) Pearce (Langney Sports), Geddes (Horsham/Ducille 73 Langney Sports), Snelgrove (Langney Sports/Allen, Langney Sports 68) Russell (Horsham YMCA)
Subs not used: Lightwood (sub keeper), Sargeant (Langney Sports), Embleton (Oving).
Royal Navy: Adams, Gamble (Frame 52) Taylor, Riley, Mather, O'Neil, Thwaite, Roberts, Richardson (Barton 46), Quirke, Johnson.
Referee: Phillip Owens (Hampshire)
Men of the Match: Russell for Sussex; Roberts for Navy
Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.
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