Liverpool ended their 85-year Manchester United jinx when a Peter Crouch header gave them a deserved 1-0 win over their fiercest rivals in the fifth round of the FA Cup at Anfield.

Liverpool had not beaten United in nine FA Cup ties spanning 85 years, including the 1996 and 1977 finals, but were always in command of a disappointing game.

The goal came in the 19th minute when England striker Crouch was left unmarked to steer in an excellent header from a cross from Irish international Steve Finnan.

United, a record 11-times winners of the Cup and runners-up last season, were desperately disappointing despite fielding an attacking side and Liverpool keeper Pepe Reina was not forced to make a worthwhile save all afternoon.

Although Liverpool face Benfica in the Champions League on Tuesday coach Raphael Benitez also put out a full-strength side.

They took control of midfield from the start and Edwin Van der Sar was at full stretch to tip a Harry Kewell header round a post in the 18th minute.

From the resulting corner the ball reached Finnan whose deep cross reached an unmarked Crouch whose excellent header went in off both posts.

Finnan had the chance to double the lead in the 25th minute but, unmarked to meet a Steven Gerrard free kick, he sidefooted into the side-netting.

Having seen his side fail to make any impression in the first half, United manager Alex Ferguson added an extra striker in the shape of Louis Saha for the second.

However, even with the later addition of Alan Smith, United continued to struggle.

Their first serious shot on goal did not arrive until the 80th minute, when Ryan Giggs pushed a right-footer over the bar.

Last month United grabbed a last-minute 1-0 league win at Old Trafford and also scored two late goals to snatch a 2-1 win in the teams' last FA Cup meeting in United's 1999 treble year.

This time though, even in seven minutes of added time, there was to be no comeback and United's bad day was completed by a late injury for Smith, who left the field on a stretcher with a broken leg and a discolated ankle.

As Smith attempted to block John Arne Riise's shot following Dietmar Hamann's free-kick, his left leg crumpled underneath him.

The makeshift midfielder needed oxygen as he was carried off on a stretcher, and Ferguson reported it was  one of the worst  injuries he had witnessed.

"He has broken his leg and dislocated the ankle joint," the United boss told MUTV. "It is a bad one. He has gone to hospital, it looks very long term - it is one of the worst I have seen. I am sure he will be back."