Kevin Keegan launched a scathing attack on Arsenal midfielder Samir Nasri following Newcastle's 3-0 English Premier League defeat on Saturday.
The Magpies manager was furious after the Frenchman scythed down Joey Barton towards the end of a lively clash at the Emirates stadium, the AFP reported.
The pair had been involved in a running spat ever since Barton's introduction as an 89th-minute substitute.
Barton was making his first appearance in Newcastle colours following his release from prison after serving a 11 weeks of a six-month sentence for assault and he was greeted with a crescendo of boos from the home fans.
He quickly announced his return with a crunching tackle on Nasri, which left the winger crumpled on the floor, and moments later, the Arsenal player took revenge by clattering into the back of Barton's legs as he broke forward.
That tackle earned a yellow card from referee Rob Styles but Keegan believed Nasri should have been sent off for the incident and duly became involved in a heated confrontation with the former Marseille player and Arsenal captain William Gallas as the sides walked off at the final whistle.
"I wasn't happy with it," Keegan said. "Joey came on, got a good tackle in on Nasri and then the guy sliced him down. That's what happened and that's what I was upset about.
"I like Nasri very much - he's a player we looked at for a possible signing last year - but you can't do things like that. If it had been the other way round, and a Newcastle player had done that, I wonder what the reaction would be.
"I know the referee didn't see it but the linesman did and it should have been a red card. I will tell Arsene Wenger the same thing when I see him and I told Nasri that at the end as well. The fact is that Joey has done nothing wrong."
Wenger, perhaps predictably, chose not to embroil himself in the controversy. "I don't know why Keegan was so angry," he said. "Nasri clipped Barton and there was a little incident between, but he was booked and rightly so."
The spat overshadowed a convincing victory for Arsenal which helped banish the memories of their tame 1-0 defeat at Fulham seven days previously.
The north Londoners were in control as soon as Robin van Persie converted an 18th-minute penalty awarded for Charles N'Zogbia's handball and the Dutch striker doubled their advantage shortly before half-time, slamming in after a clever back-heel from Emmanuel Eboue.
The points were secure mid-way through the second half when Denilson capped a flowing move with a cute finish, leaving Wenger to reflect with satisfaction on an impressive display.
"It was a complete performance - offensively and defensively," he said. "We had great balance, movement and penetration. We were in control and we played the game that we love and the game that we can play at our best.
"We could have scored more goals but I'm also pleased that we didn't concede."
The only sour note for Arsenal was sounded towards the end of the game, when van Persie had to be helped from the field with an ankle injury. The Holland striker was undergoing x-ray examinations on Saturday evening to determine whether he had broken a bone.
Wenger also confirmed that his hunt for new blood will continue, with the transfer window snapping shut on Monday night, although the Frenchman joked that the worldwide economic slow-down could prompt a re-think.
"We are trying to buy new players but the problem is always first of all, the availability and also the fact that it's finding players who are better or at least as good as the ones we already have," he said.
"And I am also scared to spend a lot of money after listening to [British Chancellor of the Exchequer] Alistair Darling - he is announcing a terrible financial hurricane is coming to England so maybe we shouldn't spend too much!"