Goals from Darren Peacock, David Ginola, Les Ferdinand, Alan Shearer and a wonderful chip from defender Phillipe Albert sealed all three points for Keegan's "Entertainers", serving as the ideal revenge for the Charity Shield defeat by the Red Devils months prior.
Sanchez was lively for the visitors and caused panic in the Newcastle box with a mazy dribble.
'The gods of football were with them but they fought lie animals to get that luck. They must have an unbelievable feeling after giving absolutely everything.
"We had some (chances) with the score at 0-0".
Joselu could return for the home side after the Spanish striker missed the trip to Selhurst Park through illness, while Slovakian goalkeeper Martin Dubravka and on-loan Leicester forward Islam Slimani could make their debuts after arriving at the club on transfer deadline day last month. After Chris Smalling conceded a free-kick for diving near the halfway line, Shelvey sent a simple long ball into the box, Gayle cushioned a loose ball into Ritchie path and he swept home completely unmarked from 12 yards out. It was an intuitive thing.
Despite his red card earlier in the season and various complaints about refereeing decisions, Mourinho said that he was mostly happy with the quality of officiating in England, although he felt players such as Alexis Sanchez could do with a little more protection.
The challenge for Newcastle now will be using this win to start a run that will put them well and truly clear of the relegation battle, while United will need to pick themselves up for their FA Cup clash with Huddersfield on Saturday.
With only 12 games to go, Manchester United must continue to stay ahead of the chasing pack and make sure they are not dragged into a scramble for the top four.
All three key to today's win and isn't it just great when a plan comes together.
"The rest of the team helped and all the players worked so hard, so to say the keeper was important is not fair for the others, everybody was important".
'But if you ask me if I think Newcastle are going to be in the Championship next season, I say immediately no way. They can punish you.