Arsenal began the second half on the front foot and four minutes after the break they found their reward. Alexis Sanchez found Aaron Ramsey with a cross into the box.
Time seemed to stand still with the whole of United's defence appealing, but the Welshman was miles onside. He unselfishly played it back for Lacazette to fire past De Gea.
Lacazette Scores! What a ball from Alexis and that run from Ramsey. pic.twitter.com/rP6qjDfj8K
— Arsenal (@DammitArsenalx) 2 de diciembre de 2017