Wigan boss Roberto Martinez has accused Manchester United striker Danny Welbeck of diving and claimed that he should have been sent off at Old Trafford this afternoon.
The initial incident happened in the first couple of minutes during United's 4-0 win, when Welbeck went down under Ali Al Habsi's challenge. It seemed innocuous at the time, and TV replays showed there had been no contact as Welbeck went to ground.
Javier Hernandez missed the penalty but later in a feisty contest, Welbeck lunged in on Franco di Santo, which Martinez felt warranted a red card.
"For Danny Welbeck's last challenge, his foot was over the ball on Franco,'' said Martinez. "It is completely reckless. Under the new regulations you cannot do that. I am not arguing whether they should be in the game or not. That is for others.
"But with the laws as they are, you cannot tackle people like that. The foot is over the ball. It is reckless and dangerous. It is a red card, for a Wigan player, Manchester United, everyone.''
Despite that, Martinez did not blame referee Michael Oliver for his side's defeat. But the Latics chief did say he was irritated at that first spot-kick call, which he felt set the tone for the entire afternoon.
"I was (irritated),'' he said. "You could see it. You know what he is trying to do. I have come to United three times before today and for whatever reason we don't seem to be measured in the same manner as the team at home.
"Today the penalty is as bad a decision as you are going to see in the Premier League. In many ways, you feel as though you are fighting against a mountain. There were tackles flying around that if they had been the other way round there would have been a couple of red cards.''
United's biggest win of the season was scarred by a short burst of anti-Liverpool chanting from a small minority of home fans.
A club spokesman said: "The manager has made the club's position very clear on this matter. It's now up to the fans to respect that. "
On Friday, though, Sir Alex Ferguson expressed the hope that, following this week's damning judgement on the Hillsborough tragedy in 1989, when 96 people died, a line could be drawn in the sand on the sour relations between the two sets of supporters.
After a scoreless first-half, Paul Scholes broke the deadlock by tapping home after Ali Al Habsi had only been able to parry Nani's low cross into his path. On his 700th United appearance, it extended a remarkable record.
"That is what we always remember about Paul, the way he ghosts into the penalty box,'' said Ferguson. "Obviously as he has got older, he has not been able to do that. He doesn't need to do that now because we prefer him to play central midfield.
"But now he has scored on his 100th, 300th, 400th, 500th and 700th appearance. It is fantastic.''
Hernandez atoned for that earlier penalty miss when he added a second before debutants Alexander Buttner and Nick Powell both found the net. Buttner was slightly fortunate, although he did surge past three players to get in position to let fly with a shot that Al Habsi should have kept out.
There was nothing lucky about Powell's effort though as the 18-year-old belted home from 20 yards.
"Nick Powell is going to be a really good player,'' said Ferguson. "He has a great temperament. He has two-feet and is quick. He is a great striker of the ball.
"For an 18-year-old boy it has been a terrific day. Alexander was a little bit rash at times but he has a great engine. He is raw and has a lot of rough edges. Hopefully we can develop that and he will be a really good addition for us.''
Ferguson confirmed that Patrice Evra had missed out through injury rather than any form concerns, although Buttner has now applied pressure for the Frenchman's previously certain first-team spot.
"I found out I was playing yesterday,'' he said. "I wasn't nervous then but when I was standing on the field looking around I was a little bit.
"It was my first goal in my first game and I will never forget it because if I play I want to let it be seen that I can do a good job.''