Sone Aluko stunned Newcastle with a stunning winner as Hull fought back to claim a famous victory at St James' Park.
The Nigerian steered an inch-perfect 76th-minute volley past keeper Tim Krul to make it 3-2 after the Tigers had twice come from behind on Tyneside.
But Magpies boss Alan Pardew will have been furious with the way his side capitulated on a day when striker Loic Remy demonstrated his potency.
The Frenchman, the club's only senior summer addition, struck twice before the break to give his side the lead, much to the delight of watching owner Mike Ashley and director of football Joe Kinnear.
However, to the horror of the bulk of a crowd of 51,523, Newcastle endured a dreadful day at the back and were made to pay for their failings.
It took Remy just 11 minutes to get his name on the scoresheet, heading home from close range after strike-partner Papiss Cisse had dragged a shot across the face of goal.
But after a promising start by the Magpies, they allowed Hull to work their way back into the game and they were level within 15 minutes when Robbie Brady was gifted time and space inside the penalty area to beat Krul.
The home side were laboured in the efforts to restore their advantage, but they did so a minute before half-time when Remy pounced on a loose ball to beat goalkeeper Allan McGregor for a second time.
But Newcastle failed to learn their lesson and were punished once again with the second half just three minutes old when former Sunderland winger Ahmed Elmohamady ran unchecked on to Brady's free-kick to level.
The home side flattered to deceive for long periods, dominating possession, but creating too little to make the pressure count as the Tigers defended deep to pave the way for Aluko's late strike.