Arsenal have finally brought in midfield reinforcements after securing the signing of long-term target Thomas Partey from Atletico Madrid.
Partey, 27, has cost Arsenal £45 million (A$81 million) after the club opted to trigger his release clause just 32 minutes before Tuesday's (AEDT) transfer deadline, and he has signed a long-term contract.
Lucas Torreira has moved in the opposite direction after agreeing to join Atletico on a season-long loan.
Ghana international Partey has long been admired by Arsenal and was said to be their primary midfield target, along with Lyon's Houssem Aouar - who has remained in France beyond the deadline.
The Gunners were reported to have made their interest known to Atletico earlier in the window, but Los Colchoneros informed them they were unwilling to negotiate his sale.
Financial constraints were said to be preventing Arsenal from simply triggering his buyout clause, but they finally stumped up the cash and got their man.
Partey came through Atletico's academy after moving from his native Ghana in 2012.
After loan spells with Real Mallorca and Almeria, he gradually became more prominent at Atleti and has been a regular in the first team for the past three seasons.
Gunners boss Mikel Arteta said of Partey: "We have been watching Thomas for a while, so we're now delighted to add such a high-quality player to our squad.
"He is a dynamic midfielder with great energy. He brings a lot of experience from a top club that has competed at the highest level in La Liga and the Champions League for several years.
"We're very impressed with his attitude and his approach to the game. He's an intelligent footballer and we're looking forward to him integrating into our system and contributing to the progress we're building at the moment at the club."