Robert Koren scored for the visitors late in the game but it was too little too late as Cardiff held on to win.
The Bluebirds got off to the perfect start after Helguson bravely headed the hosts in front from Craig Noone's cross inside three minutes.
Cardiff continued to dictate the play when Hudson headed off-target from Peter Whittingham's corner.
Whittingham continued to cause trouble from set pieces but his delivery failed to produce a goal, whereas Sone Aluko came close for the away side but neither of his efforts could find the target.
Substitute Kiss was forced off early in the second half as he was replaced by Joe Ralls.
Despite controlling much of the possession after the break, Hull failed to create any real chances as they searched for an equaliser.
Helguson had the chance to score his and his side's second goal but headed a cross harmlessly over the crossbar.
Hull mounted a late response as Koren's superb volley dipped past David Marshall to give the visitors a glimmer of hope but it proved to be too late as Cardiff held on for the victory.
Cardiff stay third following their triumph but go three points clear of Hull in fourth.