Liverpool have shown that to beat Manchester City, you must ask questions of their central defenders.
When forwards run at John Stones and Nicolas Otamendi, they can get into trouble. Until now, few have been able to get the other side of Fernandinho and expose them.
After giving Alex Oxlade-Chamberlain the space to run in and score, Otamendi punched the floor. He knew he should have done better.
For Liverpool’s second, Stones needed to be quicker and stronger up against Roberto Firmino.