LONDON (AFP) - Wayne Rooney failed to convert a penalty as Manchester United lost 3-1 on spot-kicks to second-tier Middlesbrough in the League Cup on Wednesday, while Jurgen Klopp's Liverpool edged Bournemouth.

After 120 goalless minutes at Old Trafford, the fourth-round tie went to penalties and with Rooney, Michael Carrick and Ashley Young all fluffing their lines, Championship side Middlesbrough pulled off a famous win.

United followed holders Chelsea and Arsenal in exiting the competition, while Middlesbrough set up a home quarter-final with Everton.

A low-key game that saw United manager Louis van Gaal make nine changes to his starting XI sprang to life mid-way through the second half, with home defender Daley Blind the central figure.

The Dutchman was involved in two huge scares for United, first hacking the ball into his own net, only for the goal to be ruled out for offside, and then dispatching a back-pass that stand-in goalkeeper Sergio Romero almost allowed to bobble into the net.

As the game ticked into injury time there was a flurry of chances, with Jesse Lingard hitting the post for United and Romero saving from Grant Leadbitter and Stewart Downing at the other end.

United substitute Anthony Martial had a penalty shout for handball rejected and went close with a header in extra time, and the home side were left to rue their missed opportunities.

United's first penalty was saved by Tomas Mejias and with Carrick blazing over the bar and Mejias also saving from Young, spot-kicks from Leadbitter, Downing and Ben Gibson took Aitor Karanka's men through.