Chelsea finally completed their move for Wigan forward Victor Moses after the Nigeria football international passed a medical and agreed personal terms with the European champions.
The Blues had four bids for Moses rejected by Wigan chairman Dave Whelan during the course of a fractious transfer saga that had lasted since the end of last English Premier League season.
Whelan had infuriated Chelsea by speaking publicly about the negotiations in a bid to drive up the price.
But Chelsea boss Roberto Di Matteo got his man at the fifth attempt after Wigan confirmed on Friday that they had accepted an improved offer for the 21-year-old, worth a reported $17.5 million.
Chelsea didn't announce the length of the contract for Moses, who joined Wigan from Crystal Palace in 2010 and rose to prominence after a series of impressive displays for the Latics last season.
Chelsea manager Roberto Di Matteo has already bought several attacking players in the close season including Brazilian Oscar, Belgium's Eden Hazard and Marko Marin from Germany.
The London club have won their opening two games of the season including a 2-0 win at Wigan in their first game.