City were given a break when Tamas Priskin was sent off for striking at Purse but City could not take advantage before half time.
The second half took off for City with relentless pressure on the Watford goal. The stats shown a tally of some 14 or 15 Cardiff corners to one from the home side. Efforts at goal ended 19 - 6 in City's favour as well.
Cardiff thought they would get back into the game on the hour when Whittingham was fouled and a penalty awarded. Ross McCormack failed to score from the spot for the first time this season. His effort saved by Richard Lee. No real surprise, Lee saved two penalties in Watford's 3 - 0 win at Southampton on Saturday.
Dave Jones took Whittingham off and brought on Eddie Johnson for the last 25 mins. On 72 mins Jay Bothroyd got the goal that brought City back into the game, Bothroyd's shot deflecting past the outstanding Lee. Three mins later and Bothroyd fired City level.
There looked to be only one winner but Lee held firm and produced a man of the match performance to keep City out.
The point sees City drop to 5th in the table but preserves the unbeaten away record in the league and means still just one league defeat all season.
Next up City face bottom of the table Nottingham Forest at the City Ground on Saturday and then Blackpool at Ninian Park next Tuesday. Both games City will look to takle maximum points from.