Chelsea have officially confirmed the signing of Mykhaylo Mudryk on an eight-and-a-half-year deal from Shakhtar Donetsk.
The 22-year-old has put pen to paper on the longest player contract in the club's history, agreeing terms that will keep him at Stamford Bridge until the summer of 2031 in a deal which could reportedly rise to almost £90m.
Chelsea revealed on Saturday that they were "close" to agreeing terms with the winger, having launched a late bid to hijack Arsenal's deal.
The Gunners had identified Mudryk as their number one target for the January transfer window, and were thought to be closing in on completing a club-record signing until Saturday's developments.
However, Chelsea officials flew to Turkey to conduct last-ditch talks over a move and have now officially pipped their London rivals to his signature.
"I'm so happy to sign for Chelsea," Mudryk told the club's official website.
"This is a huge club, in a fantastic league and it is a very attractive project for me at this stage of my career. I'm excited to meet my new teammates and I'm looking forward to working and learning under Graham Potter and his staff."
Chelsea chairman Todd Boehly and co-controlling owner and Behdad Eghbali added: "We are delighted to welcome Mykhailo to Chelsea. He's a hugely exciting talent who we believe will be a terrific addition to our squad both now and in the years to come.
"He will add further depth to our attack and we know he'll get a very warm welcome to London."
Chelsea announced the deal during their Premier League match against Crystal Palace at Stamford Bridge, with Potter's side aiming to end a run of three straight defeats in all competitions, and four games without a win.
Mudryk, who becomes Chelsea's fifth signing of the month already after David Datro Fofana, Benoit Badiashile, Andrey Santos and Joao Felix, has scored 10 goals and registered eight assists in 18 matches across all competitions this season.
The Ukraine international could make his debut for the Blues when they face Liverpool at Anfield next weekend.
