Patrick McCarthy has made the short trip across south-east London to join Crystal Palace from Charlton.
The 25-year-old central defender made 33 appearances at The Valley last season but Addicks boss Alan Pardew is eager to reshape his squad and has allowed the Irishman to move on for an undisclosed fee.
Just three weeks ago Mark Hudson made the opposite move when he snubbed a new contract offer from Palace to join Charlton.
Done and dusted
Having signed a three-year deal at Selhurst Park, McCarthy has spoken of his surprise at the speed with which the deal was finalised.
"The move was kind of a sudden thing, a bolt out of the blue," he told Palace's official website.
"I'm glad it's been done and dusted and that I can get my head down ready for the new season as a Crystal Palace player."