Burgess Hill Town lost 5-2 at home to Thurrock to make it seven games without a win.
Thurrock went into the break 2-0 up before Connor Tighe pulled one back on 54 minutes. The visitors then went 4-1 up when Thurrock scored two in two minutes before Aaron Smith-Joseph made it 4-2 in the 72nd minute.
But Thurrock scored again late on to finish off the scoring.
Haywards Heath Town lost more ground on leaders Haywards Heath Town as they lost 3-1 to Newhaven. Melford Simpson scored Heath's goal.
Leaders Horsham YM won 4-0 away at Worthing United.
Hassocks lost 3-1 at home to AFC Uckfield while St Francis Rangers lost 1-0 to Lingfield.