When Mateo Kovacic hobbled off in pain midway through a turgid first half it seemed like another blow to Chelsea’s rapidly disintegrating season.
Thomas Tuchel decided against sending on N’Golo Kante despite the lack of intensity in his side and sent on Ruben Loftus-Cheek to sit alongside Jorginho.
It seemed like a curious move until Loftus-Cheek’s volley fizzed into the Crystal Palace net in the 65th minute, broke open the contest and propelled Chelsea towards their third successive FA Cup final, their ninth in 16 years since it returned to Wembley Stadium.