The Gunners smashed the Hammers 5-1 at the London Stadium on Saturday, with Sanchez the inspiration behind the win.
He had a hand in four of the five goals scored by Arsene Wenger’s men, laying on Mesut Ozil’s opener before scoring a stunning hat-trick to add to the other strike from Alex Oxlade-Chamberlain.
And Sanchez’s third goal of the afternoon was definitely the icing on the cake as he put Darren Randolph on his backside with a brilliant dummy before chipping the West Ham goalkeeper.
It was so good that the West Ham ball boy behind the goal couldn’t hide his reaction to it:
Please, please look at the ballboys face as Sanchez slots that 5th in. I'm dying ? pic.twitter.com/hsuVQ4vHdu
— Savas Akay (@SavasAkayAFC) December 3, 2016
We pretty much had the exact same reaction to seeing Sanchez apply his side’s fifth.
The victory keeps Arsenal just three points behind Chelsea, who sit top of the Premier League after their 3-1 win over Manchester City yesterday afternoon.
If they can get Sanchez producing more quality like this then it could be a memorable season for the Gunners.