Liverpool's habit of conceding goals from positions of strength caused them problems again as they found themselves hanging on for a 2-1 win in the 247th Merseyside derby.
A fifth successive league victory kept the champions in an unassailable position at the top of the table but, while there was no need for any late drama of recent matches, they never appear more vulnerable than when 2-0 up.
Three times in six matches this season they have been pegged back from that position only to score added-time winners, but when Ryan Gravenberch and Hugo Ekitike scored inside 29 minutes at home to Everton it appeared it would be plain sailing.