Missed chances cost Sidley
United had enough opportunities to wrap up the game by half time after totally dominating the first 45 minutes.
Dave Carey went close for the visitors with a header that flashed over the crossbar, and Shae Spreafico should have done better but after being put clear by Jimmy Watson.
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Hide AdThe home side weathered the storm and snatched the lead on 62 minutes when Luke Johns out-jumped United keeper Danny Poole and guided a header into the net.
Wes Tate had a great chance to equalise in the final minute but Redhill keeper James Wastell made a fine stop.
Bexhill United crashed 7-0 away to Crowborough Athletic in Division Three. On target were Singer (12, 67), Lattimer (18), Baker (19), Bishop (40), Foy (81, 88).