Manchester United manager Jose Mourinho lauded his players' "beautiful football" after they overwhelmed West Ham United 4-1 to set up a League Cup semifinal date with Hull City.

United are toiling in the Premier League, where a run of four consecutive home draws has contributed to their worst start to a top-flight campaign since 1989.

But they produced some irresistible football against West Ham at Old Trafford on Wednesday, prevailing through a brace apiece from Zlatan Ibrahimovic and Anthony Martial.

"I'm pleased with the goals because the performance is something that we are used to," Mourinho told Sky Sports, before ducking his post-game press conference.

"We are playing very, very well at home and today was more of the same.

"After that goal (West Ham's equaliser), we had 10 minutes where we felt it deeply and the players on the pitch could not hide that because West Ham's first shot, they equalised.

"But in the second half the team got again the confidence to play and to win comfortably and play beautiful attacking football, which is something that the fans like. But we need results."

Mourinho was not present in the dug-out, having earlier been given a one-game touchline ban for angrily booting a water bottle during United's 1-1 draw with West Ham in the league on Sunday.

He could not be seen in the directors' box and when asked where he had watched the game, he said it was a "secret".

Meanwhile, Southampton dealt Arsenal a shock defeat in the English League Cup quarterfinals as goals from Jordy Clasie and Ryan Bertrand earned Claude Puel's side a 2-0 win.

Arsenal manager Arsene Wenger had been hoping to win the competition for the first time, but instead his decision to make 10 changes backfired as Southampton ended his side's 19-game unbeaten run.

Southampton, who also eliminated Arsenal from the competition two seasons ago, reached the semifinals after losing their last six last-eight ties in the competition.

Dutch midfielder Clasie's blistering drive put Southampton ahead in the 13th minute at the Emirates Stadium.

England left-back Bertrand added a second seven minutes before half-time, gathering Sofiane Boufal's pass and rifling a shot into the bottom corner.

It was Arsenal's first defeat since a 4-3 loss at home to Liverpool on the opening weekend of the Premier League season.