Pep Guardiola may have thought it a bad day when he suffered a fifth match without a win on Sunday but it was nothing compared to the nightmare that befell his old managerial rival Jose Mourinho on an extraordinary afternoon of Premier League action.

Guardiola's Manchester City went back to the top of the table on goal difference after a 1-1 draw at home to Southampton, leaving him to reflect glumly on a five-game winless streak for only the second time in his garlanded career.

A couple of hours later, though, his Manchester United rival Mourinho, a general not used to humiliation, was forced to sit at a ground he once commanded and see his side ripped apart 4-0 as Chelsea produced one of the standout displays of the season at Stamford Bridge.