Gardner was sent off after only 29 minutes for two bookable offences and faces a two-game ban as it was his second dismissal of the campaign.
But Blues held on for a point in their own battle for survival, with Sebastian Larsson cancelling out Steven Fletcher's early penalty.
Alex McLeish's side are now four points clear of the relegation zone with three matches to play.
But Wolves will view this as a golden opportunity wasted to climb out of the bottom three, having had the numerical advantage for such a lengthy period.
Source: PA
Source: PA