Paul Pogba vowed to learn from the costly penalty he conceded as his "stupid mistake" saw Arsenal beat Manchester United at Old Trafford on Sunday.
Arsenal ended their 29-match winless Premier League run away to big-six sides as Pierre-Emerick Aubameyang's second-half penalty sealed a 1-0 win in Manchester.
Ole Gunnar Solskjaer's 100th match at the wheel ended in a galling loss, with the Red Devils failing to win in their opening four top-flight home matches for the first time since 1972-73.
United were a shell of the side that hammered RB Leipzig in the Champions League and Mikel Arteta's Arsenal punished them, with Pierre-Emerick Aubameyang's spot-kick sealing a 1-0 win.
It was the Gunners' first league win at Old Trafford since 2006 - and first at a big-six rival since January 2015 - and gifted to them by Pogba's needless penalty-box challenge on Hector Bellerin.
"We know it's a poor performance," the midfielder told BBC Sport. "Myself, I cannot give a foul away like this.
"I thought I would touch the ball but I didn't. (I) cost us the goal today with the penalty.
"Like I say, details. We have to do better, the team, myself, it starts with me.
"I felt like I touched him a bit, I knew I was in the box, I shouldn't have given a penalty away like that.
"Maybe I was a bit out of breath, it made me do this stupid mistake. I will learn from that, I'm not the best defensively in the box, I can work on that."
Solskjaer echoed Pogba's view after a match that looked set for a 0-0 draw, just like last weekend's clash with Chelsea.
"Paul knows if he stays on his feet and he shuffles the boy... because he was on his way out of the box, it's a soft pen to give away," he said. "Those things happen.
"I know he touched him enough to give away a pen and that went against us. Paul held his hand up and he knows he could and should have done better in that instance.
"That was the difference between the teams today. It always looked like a 0-0 to me."
Additional reporting by PA.
