Arsenal also failed to pick up maximum points in a great day for United that saw them come from behind twice to win a spectacular game at Reading.
“It was crazy out there — it was not good defending at set- pieces and it could have cost us,” Rooney told The Sun.
“We had to make sure we were better in the second half and we did that.
“It probably doesn’t do the coaches or the fans any good watching that.
“But we always believed in ourselves and when we went behind twice we came back.
“Having seen the earlier results, it was important to come away from here with three points regardless of the performance.
“When you look back at it, it was like a basketball match, which maybe delighted the neutral fan.”