Rolando Aarons and substitute Moussa Sissoko struck as Newcastle dumped holders Manchester City out of the League Cup with a 2-0 win at the Etihad Stadium.
To compound City’s woes, as manager Manuel Pellegrini’s decision to field a strong side just four days before a Manchester derby backfired, key playmaker David Silva limped off injured early on.
Aarons stunned City when he capitalised on poor defending early on and the hosts, despite controlling possession and creating some chances, never truly convinced.
Newcastle were denied what seemed a clear-cut penalty in the second half but Sissoko finished the job 15 minutes from time, loosening City’s grip on the trophy with a fine finish.
Pellegrini’s men have now gone three games without a win and need to regroup with two big games in the next week against United in the Premier League and CSKA Moscow in the Champions League.
Elsewhere, Southampton continued their superb run of form with a thrilling 3-2 win over 10-man Stoke City to reach the last eight of the League Cup.
Saints took the lead after Italian Graziano Pelle curled in a stunning effort before Shane Long doubled the hosts’ advantage with his first goal for the club.
Midfielder Steven N’Zonzi gave Stoke a lifeline after the interval with a drilled effort and Mame Biram Diouf then headed an equaliser.
But when Stoke substitute Peter Crouch was sent off for collecting two yellow cards, Pelle found space from the resulting free-kick to fire an 88th-minute winner.