Bakary Sako's injury time goal earned a valuable point for Wolves but also denied a full three points to Watford.
The result means City have a seven point lead over Watford going into Saturday with two games in hand.
Palace won at Derby (who Cardiff entertain on Tuesday) and now sit nine points behind the Bluebirds having played two games more.
Not a bad night for City without even playing.
Source: Cardiff City Online