With United trailing by a single goal, the Northern Ireland star was given his marching orders moments into the second half, allowing Manchester City to ram home their numerical advantage and score five more goals to triumph 6-1 at Old Trafford.
It was an extraordinary result which reverberated around the game, moving City five points ahead of their bitter rivals at the top of the Premier League.
It didn't take long for the blame game to begin amongst United supporters.
The final whistle to call time on the demolition derby had hardly left the referee's lips when frustrated Red Devil fans started calling phone-in radio shows to vent their anger.
Ferguson took some stick for his team selection, as did United's full-backs and midfielders, but feeling most of the heat was the 23-year-old from Rathcoole with many questioning his future at the club.
Ferguson though clearly rates Evans. Why else would the Scot continue to select the Ulsterman for so many critical games since he made his league debut for the club three years ago?
Take Sunday for example. In what was a rarity this season, Ferguson had all his centre-backs available yet, knowing his team would be severely tested by Roberto Mancini's front men, he left club captain Nemanja Vidic out of the squad, the highly rated Phil Jones on the bench, chose to keep Chris Smalling at right-back and opted to play Evans alongside Rio Ferdinand at the heart of defence,
Unfortunately for the Northern Ireland international he didn't stand up to the test, giving Mario Balotelli too much space to open the scoring in the first half and then being outwitted by the controversial Italian forward after the break which led to his dismissal.
Evans protested his innocence but he knew he was guilty of poor defending, crucially allowing Balotelli to get goal-side of him as a ball was played through, and then, showing bad decision making, fouling the striker as he threatened to run clear into the box.
Being the last defender, he had to be sent off. As a distraught Evans jogged down the tunnel at Old Trafford, he was left to reflect on a massive moment in the match and a potentially defining one in his career.
Now fans are demanding Vidic re-uniting with Ferdinand or Jones playing alongside either one of them leaving Jonny out in the cold, with some suggesting he will follow others to that graveyard for United defenders Sunderland, where ironically Evans has been a huge success in two loan spells.
Former Northern Ireland manager Sammy McIlroy, who played for both City and United, believes his countryman now faces a huge test of character to establish himself again in Ferguson's side.
“Jonny has to bounce back now — at Manchester United it's expected of you. Sir Alex Ferguson will certainly expect it,” said McIlroy.
“I am sure that he can't wait to play again to put the red card behind him. He knows he has to react and prove himself again and although this is a test I believe that he is capable of having a long career at Manchester United.
“It's obvious that the manager has faith in him. Even the fact that he played against City shows that. He could have played Nemanja Vidic or Phil Jones, but he went with Jonny who has done well for him this season. I don't think one sending-off, even in such a big game, will change the manager's mind.
“This is a test of character for Jonny and we'll see how he reacts to it, but I believe that he has the strength of character to come back from this.”
Another former Northern Ireland great Mal Donaghy, who also played for United, is also backing Evans to battle back from this disappointment.
Donaghy knows all about being sent off in big games, having seen red in the epic 1982 World Cup finals clash with Spain. Unlike United though when they went down to 10 men on Sunday, Northern Ireland won their match 29 years ago.
“I can empathise with Jonny as someone who was sent-off in a World Cup finals,” said Donaghy.
“If he's anything like me he'll probably get people coming up to him for the next 30 years mentioning it because I still get it.
“Jonny will get over it. He's a professional, he'll want to get the suspension behind him as quickly as possible and it's something he'll just have to put down to experience.
“I'm sure Jonny's down on himself right now, but he should take confidence from the fact that he was in the team on Sunday while Nemanja Vidic was in the stand.
“I'm not sure if Vidic was injured, but Jonny got the nod in front of him so that shows the manager has belief in him. Vidic has been sent off a few times and always came back, so I'm sure Jonny can do the same.”
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