The Ducks went into the game under caretaker-manager Ben Williams following the departure of long-serving boss Glyn Creaser a day or so earlier (see separate news item).
And the turning point of the game came in the 23rd minute when Diamonds` striker Ben Farrell latched onto a poor back-pass and lobbed the ball over `keeper Jack Sillitoe, who almost instinctively stuck his hand up to stop the ball10 yards outside the box.
Sillitoe shown a straight red card and with no sub keeper on the bench, midfielder Greg Williams was forced to don the gloves – something he has done on more than once occasion in the past.
However, he was beaten 6 minutes later when Farrell set up his strike partner Tom Lorraine to beat Williams and give Diamonds the lead.
But the battling Ducks made it hard for their high-flying visitors and recent signing Tre Mitford forced a decent save out of Diamonds` keeper Ben Heath in the second half.
But any chance the ten-men had of causing a surprise disappeared in the 71st minute when they went down to nine-men when skipper Jack Wood was dismissed for a second bookable offence.
Williams made a series of amazing saves, including from a Joel Gyasi free-kick and double save to deny Ryan Robbins and Farrell.
The Diamonds second goal finally managed to beat the emergency keeper in the 92nd minute when Lorraine grabbed his second of the game from the edge of the area to give the visitors a sixth straight win.
By Steve Whitney