Sir Alex Ferguson said Paul Scholes suffered another of his "red-mist moments" after the veteran midfielder was dismissed in Manchester United's FA Cup exit against Manchester City.
Scholes saw red for an ugly studs-up lunge on Pablo Zabaleta's thigh as United, trailing 1-0 to Yaya Toure's strike, fought to get themselves back into a pulsating semi final at Wembley.
Afterwards, Ferguson had no complaints about the dismissal, which he attributed to Scholes notorious tendency to fly into rash tackles.
"We've seen over his career Paul has had unbelievable moments - he's one of the greatest players this club has ever had," Ferguson said.
"But he has his red-mist moments - he caught the boy on the thigh."
Ferguson insisted, however, that Scholes dismissal had not "killed the game," saying United may have snatched victory late on.
The United manager instead blamed the slack defending which led to City's winner as well two glaring misses from Dimitar Berbatov.
"The first 15 minutes after half-time cost us the game," Ferguson said.
"Slack moments. Edwin (van der Sar) had a bad kick out and Michael Carrick couldn't hold it and it was a goal.
"From then on, they were defending apart from a couple of counter-attacks. It's disappointing as we should've been ahead in the first half as we were the better team.
"The chances that Dimitar missed - there was a great save by the goalkeeper but the second chance, from under the bar, if he'd have scored there, I had a feeling whoever scored first would win the match."
Ferguson insisted United would need to bounce back from the disappointment against Newcastle in the Premier League.
"It's a major game on Tuesday up at Newcastle," he told MUTV. "We're getting recovered to get ready for the game on Tuesday.
"It doesn't matter when you play, you know you've got to recover and get on a winning streak again."