A controversial first half penalty was enough for Boreham Wood as ten-man Wrexham succumbed to a second home defeat of the season.
Bruno Andrade converted from the spot after Manny Smith was adjudged to have commited a foul in the box.
After the break as Kevin Roberts saw red, there was no way back for the Reds, whose unbeaten run came to an underwhelming end. The result saw Andy Davies' side fall to fourth in the National League standings.
Boreham Wood started the better of the two sides, attempting to put some early pressure on Wrexham's backline. The hosts struggled to get out of their own half in the early stages and were behind after ten minutes.
Smith was deemed to have pushed a Boreham Wood player in the box and the referee, contoversially, pointed to the spot. Andrade stepped up and converted confidently.
The visitors continued to enjoy the better of the contest having taken the lead, maintaining a compact shape and offering a threat on the break. Wrexham, by contrast, were unable to create anything of note and grew increasingly frustrated with the officials.
Andrade, dangerous throughout, guided a shot wide inside 20 minutes having been picked out in the box. And on the half-hour mark, Boreham Wood came close to doubling their lead when Tom Champion glanced a header across goal from a corner.
Wrexham gradually improved, although not enough to concern the away side. Scott Quigley managed two efforts off target as half time approached, but the Reds had struggled to break down a solid Boreham Wood outfit.
The second half began with more controversy. Roberts and Andrade appeared to clash near the touchline, and it was the latter who fans expected to be punished. But, to the surprise of the increasingly incensed Wrexham supporters, the referee brandished a red card for Roberts.
The reason for the sending off was unclear, but it allowed Boreham Wood to control the game for much of the second half. The visitors were content to sit on their lead, although, making use of their extra man, they created the better opportunities.
Chris Dunn was forced to keep out an Andrade free kick on the hour mark, and Boreham Wood continued to ask questions of the Wrexham defence with a succession of set pieces.
The Reds appeared to have gathered some momentum when, with 74 minutes played, Quigley burst forward and saw his shot deflected just wide. But they could not create a clear chance, and Boreham Wood were able to see out the final minutes to secure the victory.
Wrexham: Dunn, Jennings, Smith, Pearson, Wedgbury, Quigley (Mackreth), Holroyd, Franks (Raven), Kelly, Roberts, Boden (Ainge)
Subs: Rutherford, Wright
Boreham Wood: Smith, Smith, Woodards, Ricketts, Stephens, Shakes, Champion, Murtagh, Andrade, Turley, Ferrier
Subs: Harfield, Quigley, Folivi, Doe, Davey
Referee: Paul Marsden