Will Dean was shown a straight red card towards the end of Truro’s goalless draw with Tamworth.
The City midfielder was adjudged to have swung an arm at an opponent seven minutes from full-time.
Moments later Brandon Forbes almost won it for the visitors, only to see his free-kick saved by goalkeeper Aidan Stone.
Ben Acquaye went closest for the Lambs in the first half when his shot hit the side-netting.