Antonio Conte's side were 3-0 up at Huddersfield. He wanted to rest his best players. So the Chelsea manager took off Eden Hazard, N'Golo Kante... and Andreas Christensen.
The 21-year-old defender has had a stunning rise this season, going from highly-rated prospect to Chelsea's most important defender. He has supplanted David Luiz at the back.
Just this summer there would have been questions over him. A successful two-year loan spell at Borussia Monchengladbach had come to an end. His club are not the best for putting those returning loanees into the team.