Chasetown FC suffered their third consecutive defeat in the league after an inspired performance from Leek goalkeeper Ben Chapman.
The visitors opened the scoring in the 17th minute when neat build-up play involving Danny Smith and Tim Grice was finished off by James Curley.
Chapman made the first of a number of fine saves to deny a Josh Ruff header and then dashed out to palm aside a Sam Belcher shot.
Just short of the hour the visitors doubled their lead. Sam Grimshaw slid a pass through to Jordan Johnson who fired past Curtis Pond.
Substitute Pierce Kiembi forced Chapman into a save within seconds of his introduction with a header from eight yards.
Chasetown had a golden opportunity to reduce the deficit after Mike Williams was pushed to the floor by a Leek defender – but James Dance skied the spot kick over the bar.
Tim Grice punished Chasetown with an immediate goal to increase Leek’s lead with a chipped effort.
Chapman made another great save to keep out a Kiembi header after initially punching Jack Langston’s free kick away.