Lanky England striker Peter Crouch netted twice for six-times winners Liverpool, who joined West Ham United in the last four after the London club beat Manchester City 2-1 on Monday.

It was Liverpool's biggest away win in the FA Cup and equal second biggest at any ground after their 8-0 home victory over Swansea in January 1990.

Tuesday's match had barely started when Steven Gerrard floated in a free-kick from the left, Mohamed Sissoko nodded the ball on and unmarked defender Sami Hyypia headed home for the visitors.

Mali midfielder Sissoko was making his first appearance, wearing protective glasses, since an injury to his right eye exactly a month ago that had initially threatened to end his career.

Crouch made it 2-0 when his header from Gerrard's right-wing cross was parried by Maik Taylor but the keeper could not prevent the ball from crossing the line.

The 25-year-old Crouch notched his fourth goal in three games seven minutes before the interval when he steered the ball past Taylor after Luis Garcia had slipped a perfect pass into his path.

Fernando Morientes, who came on for Crouch in the 56th minute, added the fourth following a dummy by Garcia.

Left back John Arne Riise struck a blistering fifth 20 minutes from time after running on to a neat flick from Gerrard.

Seven minutes later, City substitute Olivier Tebily tried to block Harry Kewell's low cross but only succeeded in turning the ball into his own net.

One minute from time, Taylor let a shot from the right by substitute Djibril Cisse slip under his body for the seventh, rounding off a nightmare evening for the home side who are also fighting for survival in the Premier League.