A review of Wednesday night's action in the EFL Cup as United won the Manchester derby and West Ham beat Chelsea.
Juan Mata's strike gave Manchester United manager Jose Mourinho a timely boost as their 1-0 EFL Cup fourth-round win over Manchester City stretched their alarming winless streak to six matches.
The need of both sides for a win added intrigue to an already mouth-watering derby, with Pep Guardiola's men unable to eke out victories of late and United reeling from Sunday's 4-0 humiliation at Chelsea.
Mata struck when Zlatan Ibrahimovic stayed strong in a duel that left Nicolas Otamendi on the deck, then continued to send in a low cross that Ander Herrera missed as he clashed with Fernando. Referee Mike Dean waved away calls for a foul and the Spaniard swept home convincingly.
Clashes between rival supporters marred West Ham's 2-1 win over Chelsea at the London Stadium.
Skirmishes broke out towards the end of the Hammers' impressive triumph as police and stewards battled to maintain segregation behind the goal being defended by West Ham.
Goals from Cheikhou Kouyate and Edimilson Fernandes put the Hammers in control before Gary Cahill struck a consolation four minutes into stoppage time.
Sofiane Boufal marked his St Mary's debut with a stunning strike to fire Southampton into the last eight after a 1-0 win over Sunderland.
The club's record signing, whose introduction to English __football has been delayed by injury, curled in a sensational effort in front of a half-empty stadium.
With the prospect of extra time beginning to loom large Boufal finally broke the deadlock when he controlled an up-and-under from James Ward-Prowse superbly, stepped around Billy Jones, looked up and curled an unstoppable shot over the diving Jordan Pickford and inside the far post.
To add to their problems the Black Cats had manager David Moyes sent to the stands after they were denied a late penalty.
EFL Cup Quarter-Final Draw
- Ties to be played week commencing November 28
Liverpool v Leeds
Manchester United v West Ham
Hull City v Newcastle United
Arsenal v Southampton
EFL Cup Results: Wednesday October 26
- Click on each scoreline for the full match report
Southampton 1-0 Sunderland
Manchester United 1-0 Manchester City
West Ham 2-1 Chelsea
EFL Cup Results: Tuesday October 25
- Click on each scoreline for the full match report
Liverpool 2-1 Tottenham
Arsenal 2-0 Reading
Bristol City 1-2 Hull City
Newcastle 6-0 Preston
Leeds 2-2 Norwich - AET, Leeds win 3-2 on penalties