Arsenal fans fumed on social media on Thursday night after they were not awarded a penalty for Harry Maguire's tug on Takehiro Tomiyasu in their 3-2 loss at Manchester United.
The Gunners threw away a lead at Old Trafford to lose to their old rivals, with Cristiano Ronaldo netting twice in the second-half, including a 70th minute penalty after Martin Odegaard's foul on Fred.
Late in the first-half, with the scores locked at 1-1, United captain Maguire was seen pulling back Tomiyasu at an Arsenal free-kick and the Japanese full-back went down in the penalty area.