The Magpies' lack of leadership and quality back-up players was clearly evident and this promises to be a long season.
A Marlon King double did the trick before a Newcastle consolation from new boy Xisco was too little and too late.
The demonstrations took place as expected outside of the ground before the match started and fell on deaf ears as there was no sign of either owner Mike Ashley or unpopular director of football Dennis Wise.
Chris Hughton took charge of United after last-gasp talks between Ashley and Kevin Keegan failed to see the former manager return to the St James' Park hot-seat.
Newcastle handed a debut up front to Spain Under-21 striker Xisco, while Ignacio Gonzalez had to make do with a place on the bench.
Hull were urged on by 3,000 travelling fans but had a less than ideal build-up to the match having left their team hotel late on Friday evening following excessive noise from a wedding party.
And to compound the Hull problems, referee Andre Marriner was unhappy that their strip clashed with Newcastle's and made the Tigers wear the white shorts and white socks from the home team's away strip.
As soon as the match started, the ground reverberated to the chants of :"There's only one Kevin Keegan" along with "sack the board" making it perfectly clear where the fans' allegiance lay.
Hull were not phased by the atmosphere and created a good opening for deadline signing Peter Halmosi only for David Edgar to get in a timely block just inside the area.
Newcastle's first chance came after 13 minutes when a Charles N'Zogbia corner picked out Xisco, who was handed a free header that he put well over.
Xisco was then given a great shooting opportunity when set up by Geremi but dwelt too long on the ball and lost possession.
Geremi was largely responsible for all Newcastle's good forward play and created an opening for Danny Guthrie after 18 minutes, but the former Liverpool midfielder pulled his effort wide.
Boaz Myhill came to Hull's rescue on the half-hour mark when going to his right he kept out a close range Michael Owen header from an N'Zogbia free-kick.
But it was Hull who went in front three minutes later from the penalty spot after Halmosi was needlessly sent sprawling by Nicky Butt as United conceded a spot-kick for the third successive league match.
It was left to King to take the kick and he must have feared the worst when Shay Given guessed correctly to his left only to see the ball turned onto the upright and into the net.
It went from bad to worse for Newcastle when Hull stormed into a 2-0 lead after 55 minutes when Bernard Mendy carefully slipped King into the clear and beat the offside trap to charge forward and curl his shot beyond Given.
A fluke almost brought United back into the game after 58 minutes when Guthrie twisted and turned on the left and crossed for Myhill at full stretch to palm the ball onto the bar before it was scrambled clear.
Absolutely nothing had been seen of Newcastle as an attacking force in the second half before they were thrown a lifeline after 82 minutes when Xisco stabbed a rebound into the net after N'Zogbia had hit the post.
As they became more frustrated tempers flared in the dying seconds and United's Guthrie was shown a straight red for lashing out at Craig Fagan.