In-demand McLeod's 30th-minute opener came from the penalty spot after he was brought down by David Artell, who was shown red for the challenge.
Matters went from bad to worse for the Alex as fellow centre-back Adam Dugdale was then given his marching orders on the stroke of half-time for a late lunge on Ricky Holmes.
But despite their numerical advantage, it took until 13 minutes from time for the Bees to stretch their lead and make sure of a fourth win on the spin.
After home skipper Mark Hughes had hit the post just minutes earlier, Michael Hector's strike from Holmes' left-wing cross to the back post settled matters.
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