In doing so, the Reds also put an end to the visitors' unbeaten start to the new campaign.
An opening goal from Antony on his debut gave Erik ten Hag's side the lead going into the break.
Arsenal pulled one back on the hour mark, but a Marcus Rashford brace sealed the win at Old Trafford.
FIRST HALF Martin Odegaard dispossesed Christian Eriksen on the half-way line, with Bukayo Saka picking the ball up and slotting it through our defence to find Gabriel Martinelli who comfortably finished beyond David De Gea.
As is expected from a clash between two football giants, the opening 15 minutes was frantic. Despite the Reds starting well, it was Arsenal who almost struck first.