Lee Tomlin was sent off for violent conduct just before half-time and captain Curtis Woodhouse was shown a second yellow card just after the break.
Histon had gone ahead on 15 minutes due to Antonio Murray and they made it 2-0 thanks to another header from Jack Midson on 52 minutes.
Diamonds substitute Michael Corcoran pulled one back on 63 minutes but they could not produce an equalizer.
Read the full match verdict in Tuesday's Evening Telegraph.
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