The two out-of-favor players are swapping clubs in a sensational deal in the Premier League.
Manchester United have officially confirmed the deal to sign Arsenal forward Alexis Sanchez, while Arsenal have also confirmed the signing of Henrikh Mkhitaryan on a long-term contract.
United attacker Mkhitaryan has agreed to move to the Emirates as part of the transfer, with the deal being completed in a rare straight swap agreement.
Sanchez becomes the first player since Robin van Persie to make the move from the Emirates to Old Trafford, and will be handed United's famous No. 7 shirt. Reports have been rife over the details of his contract, with some suggesting he has signed a deal worth £14m-a-season.
Meanwhile Mkhitaryan, who joined United from Borussia Dortmund a season and a half ago, will join up with another former United forward in Danny Welbeck at the Emirates.
Manchester City had been publicly courting Sanchez for several months, with Pep Guardiola's side widely expected to sign him when his Arsenal contract was set to expire in June 2018. City had agreed personal terms with Sanchez and a large signing on fee as part of their deal, but United then swooped in to try and sign him six months early.
Jose Mourinho's side however sensed an opportunity to beat their city rivals to Sanchez earlier this month, offering a far more handsome financial package than the Premier League leaders were willing to. City walked away from the deal at the end of last week.
United also fought off late reported interest from league rivals Chelsea in order to complete the deal.