Manchester United have signed Alexis Sanchez from Arsenal, in a swap deal with midfielder Henrikh Mkhitaryan.
Chile forward Sanchez, 29, who almost joined Manchester City last summer, has signed a four-and-a-half-year deal worth £14m a year after tax.
City ended their interest last week as they felt making him their best-paid player may affect team spirit.
Mkhitaryan, 29, moves in the opposite direction to Sanchez after scoring 13 goals in 63 appearances for United.
The Armenia international moved to Old Trafford from Borussia Dortmund for £26.3m in July 2016.
He has made only 10 Premier League starts this season, and it is understood there was a breakdown in trust between him and United manager Jose Mourinho, which was reported by the BBC.
United’s signing of Sanchez, who will wear the number seven shirt, was announced on the club’s Twitter account with him playing ‘Glory, Glory Man Utd’ on a piano.
He will be available for in the Red Devils’ FA Cup fourth-round tie at Yeovil Town on Friday, which will be shown live on BBC One from 19:30 GMT.
And the League Two club tweeted a picture of their sparse-looking away dressing room with the message: “You said you’ve joined “the biggest club in the world” so it’s only right you start your United career in the biggest away dressing room in League Two – *maybe.”
Sanchez has scored 80 times for Arsenal since joining from Barcelona for £30m in July 2014, and was last season’s top scorer with 30 goals in all competitions.
“I am thrilled to be joining the biggest club in the world,” said Sanchez. “The chance to play in this historic stadium and to work with Jose Mourinho was something I could not turn down.
“I am very proud to be the first Chilean player ever to play for United’s first team, and I hope I can show our fans all around the world why the club wanted to bring me here.”
Sanchez almost teamed up at City with former Barcelona boss Pep Guardiola in a £60m move last summer, but his deadline-day transfer collapsed when Arsenal failed to sign Monaco midfielder Thomas Lemar.
Since that move did not materialise, Sanchez has had less of an impact, scoring 0.37 goals per game compared to 0.63 last season, with several pundits commenting on his on-field demeanour.