The Magpies were relegated for the second time in six years.
The Black Cats, in 17th position, went into the clash knowing that a victory would condemn their bitter North-East rivals, and indeed Norwich City, to the second tier.
And Sam Allardyce's side went about their task in ruthless fashion as goals from Patrick van Aanholt and Lamine Kone helped them into a 2-0 half-time lead, before the latter effectively finished the contest in the second half by adding a third.
Their survival, coupled with Newcastle's demotion, made the night twice as sweet for Sunderland fans, whereas for the Magpies it's a case of starting again in the Championship.
Rafael Benitez's side drew 0-0 at Aston Villa - who had lost their previous 11 Premier League games to that - on Saturday in a result which seems to be the one which ultimately sealed their fate.
Newcastle players of the past and present have aired their disappointment, with former midfielder Rob Lee and current goalkeeper Rob Elliot reacting on Twitter this morning.
Absolutely gutted! We have to come back stronger and put things right! #Nufc— Robert Elliot (@the_dilsh) May 12, 2016
Unbelievable ! Feel sorry for all Newcastle fans this morning! They deserve so much better— Rob Lee (@7RobLee) May 12, 2016
Of course, the question is now whether United can convince manager Benitez - who only replaced Steve McClaren in March, meaning it was perhaps too late - to stick around even in the Championship.