Manchester United boss Sir Alex Ferguson said his side had been surprised by the pace and aggression of Arsenal's start in the 1-1 draw at the Emirates.
The Gunners took the lead through Theo Walcott after only two minutes, but champions United hit back shortly before the break when the returning Robin van Persie smashed home a penalty.
Ferguson told Sky Sports: "The first 20 minutes, I think we were surprised at some of their aggression and tackles.
"I think that Arsenal set off at a fantastic pace, very aggressive and a lot of tackles, and I think the referee [Phil Dowd] just couldn't keep up."
Ferguson criticised Dowd for booking five United players - Phil Jones, Rafael, Van Persie, Jonny Evans and Antonio Valencia - saying: "When we have a foul, he's booked us right away.
"We have one of the best disciplinary records in the country. For Man Utd to have five players booked, I don't think that's right.''
Arsenal manager Arsene Wenger said his players had been committed and that "from the first to the last minute, it was two teams giving absolutely everything to win".
"We gave everything and, at the end of the day, the regret you have is the way we conceded the goal just before half-time," Wenger said. "That was a serious blow to us."
He had urged the home fans to show respect to former player Van Persie, but the Dutchman was booed throughout the game and the manager described that as "disappointing".
Goalscorer Walcott said he was happy with the point his strike had earned, adding: "There are still three very important games left. We have just got to concentrate on ourselves.
"I think if you look back, both teams will think it was fair. Both teams didn't really want to lose the game. Overall, it will be a good point come the end of the season."
Information from the Press Association was used in this report